It was pointed out by 'make versioncheck' that some includes of
linux/version.h were not needed in fs/ (fs/btrfs/ctree.h and
fs/omfs/file.c).

This patch removes them.
Signed-off-by: NJesper Juhl <jj@chaosbits.net>
Acked-by: NBob Copeland <me@bobcopeland.com>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>