prlimit called without a new value fails on 32-bit machines if any of
the soft or hard limits are infinity. This is because prlimit does not
translate old_rlimit from RLIM64_INFINITY to RLIM_INFINITY, but checks
that the value returned by the prlimit64 syscall fits into a 32-bit
value, like it is done for example in getrlimit. Note that on the
other hand new_rlimit is correctly translated from RLIM_INFINITY to
RLIM64_INFINITY before calling the syscall.
This patch fixes that.
Changelog:
[BZ #22678]
* sysdeps/unix/sysv/linux/prlimit.c (prlimit): Translate
old_rlimit from RLIM64_INFINITY to RLIM_INFINITY.