Fix issues identified by Coverity
- Always munmap memory regions after mmap'ing them.
- Make sure getpagesize() returns a value greater than 0 and use a cached value instead of always calling getpagesize(3).
- Remove intermediate variable for assigning from $TMPDIR if set in the environment to eliminate warnings about pointer conversions with "/tmp", and to mute an invalid buffer overflow concern from Coverity (snprintf and tacking on a NUL terminator was alleviating that concern before).
- Remove useless self-test of psize before it's initialized.
- Check the return values of getrlimit/setrlimit.
Cosmetic changes:
- Replace a (void*)0 with NULL.
- Do some minor whitespace clean up.
- Remove an unnecessary cast to mmap.
CID: 1331351, 1331382-1331386, 1331513, 1331514, 1331565, 1331583, 1331694
MFC after: 2 weeks
Reported by: Coverity
Sponsored by: EMC / Isilon Storage Division