[PATCH] md: remove unneeded NULL checks before kfree

This patch removes some unneeded checks of pointers being NULL before
calling kfree() on them.  kfree() handles NULL pointers just fine, checking
first is pointless.

Signed-off-by: Jesper Juhl <juhl-lkml@dif.dk>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>