MFC r290190,r290251:

r290190:

Fix compiler warnings with open_to_operation.c

Other sidenotes:
- Remove unused variables with main(..)
- Convert errx/exit with -1 to errx/exit with 1
- Fix a bogus test in try_directory_open
(expected_errno == expected_errno -> errno == expected_errno) [*]
- Fix some warnings related to discarded qualifiers
- Remove a bogus else-statement at the end of check_mmap_exec(..) in the
successful case. mmap(2), POSIX, Linux, etc all don't state what the
behavior is when mixing O_WRONLY + PROT_EXEC, so assume success for now to
get the test program to pass again.

PR: 201286 [*]
Submitted by: David Binderman <dcb314@hotmail.com>
Sponsored by: EMC / Isilon Storage Division

r290251:

Use nitems(x) instead of sizeof(x)/sizeof(x[0])

Sponsored by: EMC / Isilon Storage Division

MFC r264400,r265836:

r264400:

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

r265836:

Remove last two NO_MAN= in the tree. In both of these cases, MAN= is
what is needed.

MFC r264400,r265836:

r264400:

NO_MAN= has been deprecated in favor of MAN= for some time, go ahead
and finish the job. ncurses is now the only Makefile in the tree that
uses it since it wasn't a simple mechanical change, and will be
addressed in a future commit.

r265836:

Remove last two NO_MAN= in the tree. In both of these cases, MAN= is
what is needed.