fs/affs/amigaffs.c: remove unneeded initialization

bh is initialized unconditionally in affs_remove_link()

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>