Some missing parentheses and one itertools.imap (Py2) vs map (Py3) issue.
gdb/ChangeLog:
* python/lib/gdb/command/unwinders.py: Add parentheses.
gdb/testsuite/ChangeLog:
* gdb.python/py-framefilter.py (ErrorFilter.filter): Use map function
if itertools.imap is not present.
* gdb.python/py-objfile.exp: Add parentheses.
* gdb.python/py-type.exp: Same.
* gdb.python/py-unwind-maint.py: Same.