staging/lustre/libcfs: Adjust NULL comparison codestyle

All instances of "x == NULL" are changed to "!x" and
"x != NULL" to "x"
Also removed some redundant assertions.

Signed-off-by: Oleg Drokin <green@linuxhacker.ru>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
15 files changed