fs/befs/io.c:befs_bread_iaddr(): remove unneeded initialization to NULL

bh is reinitialized by sb_bread() so no need to init it
with NULL in the beginning of befs_bread_iaddr()

Link: http://lkml.kernel.org/r/586d2639d729345b9c07aac10ba713d8ceb8745a.1462841692.git.salah.triki@acm.org


Signed-off-by: Salah Triki <salah.triki@acm.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>