ext4: remove unneeded variable "err" in ext4_mb_release_inode_pa()

The err is not used after initalization. So just remove the variable.
Signed-off-by: zhong jiang <zhongjiang@huawei.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -3801,7 +3801,6 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
 	ext4_group_t group;
 	ext4_grpblk_t bit;
 	unsigned long long grp_blk_start;
-	int err = 0;
 	int free = 0;
 
 	BUG_ON(pa->pa_deleted == 0);
@@ -3842,7 +3841,7 @@ ext4_mb_release_inode_pa(struct ext4_buddy *e4b, struct buffer_head *bitmap_bh,
 	}
 	atomic_add(free, &sbi->s_mb_discarded);
 
-	return err;
+	return 0;
 }
 
 static noinline_for_stack int