Fix and sort variables in Makefiles

Fix variables in Makefiles:

1. There is a tab, not a space, between "variable" and =, +=, :=.
2. The last entry doesn't have a trailing \.

and sort them.

Signed-off-by: H.J. Lu <hjl.tools@gmail.com>

argp/Makefile

@@ -22,7 +22,7 @@ subdir	:= argp
 
 include ../Makeconfig
 
-headers	= \
+headers = \
   argp.h \
   bits/argp-ldbl.h \
   # headers

catgets/Makefile

@@ -22,7 +22,7 @@ subdir	:= catgets
 
 include ../Makeconfig
 
-headers	= \
+headers = \
   nl_types.h \
   # headers
 routines = \

locale/Makefile

@@ -48,7 +48,7 @@ tests = \
   tst-duplocale \
   tst-locname \
   # tests
-tests-container	= \
+tests-container = \
   tst-localedef-path-norm \
   # tests-container
 categories = \

math/Makefile

@@ -22,28 +22,28 @@ subdir		:= math
 include ../Makeconfig
 
 # Installed header files.
-headers	:= \
-  math.h \
-  bits/mathcalls.h \
-  fpu_control.h \
-  complex.h \
+headers := \
   bits/cmathcalls.h \
-  fenv.h \
   bits/fenv.h \
-  bits/mathdef.h \
-  tgmath.h \
-  bits/math-vector.h \
-  finclude/math-vector-fortran.h \
-  bits/libm-simd-decl-stubs.h \
-  bits/iscanonical.h \
+  bits/floatn-common.h \
+  bits/floatn.h \
   bits/flt-eval-method.h \
   bits/fp-fast.h \
   bits/fp-logb.h \
+  bits/iscanonical.h \
+  bits/libm-simd-decl-stubs.h \
   bits/long-double.h \
+  bits/math-vector.h \
   bits/mathcalls-helper-functions.h \
-  bits/floatn.h \
-  bits/floatn-common.h \
-  bits/mathcalls-narrow.h
+  bits/mathcalls-narrow.h \
+  bits/mathcalls.h \
+  bits/mathdef.h \
+  complex.h \
+  fenv.h \
+  finclude/math-vector-fortran.h \
+  fpu_control.h \
+  math.h \
+  tgmath.h \
   # headers
 
 # FPU support code.

misc/Makefile

@@ -23,62 +23,62 @@ subdir	:= misc
 
 include ../Makeconfig
 
-headers	:= \
-  sys/uio.h \
-  bits/uio-ext.h \
-  bits/uio_lim.h \
-  sys/ioctl.h \
-  bits/ioctls.h \
-  bits/ioctl-types.h \
-  sys/ptrace.h \
-  sys/file.h \
-  sys/dir.h \
-  sys/cdefs.h \
-  ar.h \
+headers := \
   a.out.h \
-  libgen.h \
-  stab.h \
-  bits/stab.def \
-  sgtty.h \
-  ttyent.h \
-  paths.h \
-  sys/reboot.h \
-  sys/mman.h \
-  sys/param.h \
-  bits/param.h \
-  fstab.h \
-  mntent.h \
-  search.h \
-  err.h \
-  error.h \
-  sys/queue.h \
-  sysexits.h \
-  syscall.h \
-  sys/syscall.h \
-  sys/swap.h \
-  sys/select.h \
-  sys/sysinfo.h \
-  regexp.h \
-  bits/select.h \
-  bits/mman.h \
-  sys/xattr.h \
-  syslog.h \
-  sys/syslog.h \
-  bits/syslog-decl.h \
-  bits/syslog.h \
-  bits/syslog-ldbl.h \
-  bits/syslog-path.h \
-  bits/error.h \
-  bits/select-decl.h \
-  bits/select2.h \
-  bits/hwcap.h \
-  sys/auxv.h \
-  sys/sysmacros.h \
-  bits/sysmacros.h \
-  bits/types/struct_iovec.h \
+  ar.h \
   bits/err-ldbl.h \
   bits/error-ldbl.h \
+  bits/error.h \
+  bits/hwcap.h \
+  bits/ioctl-types.h \
+  bits/ioctls.h \
+  bits/mman.h \
+  bits/param.h \
+  bits/select-decl.h \
+  bits/select.h \
+  bits/select2.h \
+  bits/stab.def \
+  bits/syslog-decl.h \
+  bits/syslog-ldbl.h \
+  bits/syslog-path.h \
+  bits/syslog.h \
+  bits/sysmacros.h \
+  bits/types/struct_iovec.h \
+  bits/uio-ext.h \
+  bits/uio_lim.h \
+  err.h \
+  error.h \
+  fstab.h \
+  libgen.h \
+  mntent.h \
+  paths.h \
+  regexp.h \
+  search.h \
+  sgtty.h \
+  stab.h \
+  sys/auxv.h \
+  sys/cdefs.h \
+  sys/dir.h \
+  sys/file.h \
+  sys/ioctl.h \
+  sys/mman.h \
+  sys/param.h \
+  sys/ptrace.h \
+  sys/queue.h \
+  sys/reboot.h \
+  sys/select.h \
   sys/single_threaded.h \
+  sys/swap.h \
+  sys/syscall.h \
+  sys/sysinfo.h \
+  sys/syslog.h \
+  sys/sysmacros.h \
+  sys/uio.h \
+  sys/xattr.h \
+  syscall.h \
+  sysexits.h \
+  syslog.h \
+  ttyent.h \
   # headers
 
 routines := \

posix/Makefile

@@ -360,7 +360,7 @@ tests-time64 := \
   tst-wait4-time64 \
   # tests-time64
 
-xtests	:= \
+xtests := \
   tst-sched_rr_get_interval \
   # xtests
 
@@ -405,7 +405,7 @@ install-bin := \
   getconf \
   # getconf
 
-install-others-programs	:= \
+install-others-programs := \
   $(inst_libexecdir)/getconf \
   # install-others-programs