ext4: simplify calculation of blkoff in ext4_mb_new_blocks_simple

We try to allocate a block from goal in ext4_mb_new_blocks_simple. We
only need get blkoff in first group with goal and set blkoff to 0 for
the rest groups.
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://lore.kernel.org/r/20230303172120.3800725-21-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -5773,9 +5773,6 @@ static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle,
 			return 0;
 		}
 
-		ext4_get_group_no_and_offset(sb,
-			max(ext4_group_first_block_no(sb, group), goal),
-			NULL, &blkoff);
 		while (1) {
 			i = mb_find_next_zero_bit(bitmap_bh->b_data, max,
 						blkoff);
@@ -5790,6 +5787,8 @@ static ext4_fsblk_t ext4_mb_new_blocks_simple(handle_t *handle,
 		brelse(bitmap_bh);
 		if (i < max)
 			break;
+
+		blkoff = 0;
 	}
 
 	if (group >= ext4_get_groups_count(sb) || i >= max) {