ocfs2: remove redundant assignment to variable bit_off

Variable bit_off is being assigned a value that is never read, it is being
re-assigned a new value in the following while loop.  Remove the
assignment.  Cleans up clang scan build warning:

fs/ocfs2/localalloc.c:976:18: warning: Although the value stored to
'bit_off' is used in the enclosing expression, the value is never
actually read from 'bit_off' [deadcode.DeadStores]

Link: https://lkml.kernel.org/r/20230622102736.2831126-1-colin.i.king@gmail.com
Signed-off-by: Colin Ian King <colin.i.king@gmail.com>
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Cc: Mark Fasheh <mark@fasheh.com>
Cc: Joel Becker <jlbec@evilplan.org>
Cc: Junxiao Bi <junxiao.bi@oracle.com>
Cc: Changwei Ge <gechangwei@live.cn>
Cc: Gang He <ghe@suse.com>
Cc: Jun Piao <piaojun@huawei.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>

Author: ColinIanKing

fs/ocfs2/localalloc.c

@@ -973,7 +973,7 @@ static int ocfs2_sync_local_to_main(struct ocfs2_super *osb,
 	la_start_blk = ocfs2_clusters_to_blocks(osb->sb,
 						le32_to_cpu(la->la_bm_off));
 	bitmap = la->la_bitmap;
-	start = count = bit_off = 0;
+	start = count = 0;
 	left = le32_to_cpu(alloc->id1.bitmap1.i_total);
 
 	while ((bit_off = ocfs2_find_next_zero_bit(bitmap, left, start))