[PATCH] Remove NULL check in register_nls()

Everybody passes valid pointer there.

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Acked-by: OGAWA Hirofumi <hirofumi@mail.parknet.co.jp>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>