[PATCH] udf_find_entry() cleanup

udf_find_entry can never be called with a NULL argument, so we shouldn't
check for it.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>