btrfs: remove err variable from do_relocation

It simply gets assigned to 'ret' in case of errors. The flow of the
while loop is not changed by this commit since the few call sites
that 'goto next' will simply break from the loop.
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/relocation.c

@@ -2181,8 +2181,7 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 	u32 blocksize;
 	u64 bytenr;
 	int slot;
-	int ret;
-	int err = 0;
+	int ret = 0;
 
 	BUG_ON(lowest && node->eb);
 
@@ -2200,10 +2199,8 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 		if (upper->eb && !upper->locked) {
 			if (!lowest) {
 				ret = btrfs_bin_search(upper->eb, key, &slot);
-				if (ret < 0) {
-					err = ret;
+				if (ret < 0)
 					goto next;
-				}
 				BUG_ON(ret);
 				bytenr = btrfs_node_blockptr(upper->eb, slot);
 				if (node->eb->start == bytenr)
@@ -2215,10 +2212,8 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 		if (!upper->eb) {
 			ret = btrfs_search_slot(trans, root, key, path, 0, 1);
 			if (ret) {
-				if (ret < 0)
-					err = ret;
-				else
-					err = -ENOENT;
+				if (ret > 0)
+					ret = -ENOENT;
 
 				btrfs_release_path(path);
 				break;
@@ -2238,10 +2233,8 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 			btrfs_release_path(path);
 		} else {
 			ret = btrfs_bin_search(upper->eb, key, &slot);
-			if (ret < 0) {
-				err = ret;
+			if (ret < 0)
 				goto next;
-			}
 			BUG_ON(ret);
 		}
 
@@ -2252,7 +2245,7 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 		"lowest leaf/node mismatch: bytenr %llu node->bytenr %llu slot %d upper %llu",
 					  bytenr, node->bytenr, slot,
 					  upper->eb->start);
-				err = -EIO;
+				ret = -EIO;
 				goto next;
 			}
 		} else {
@@ -2263,7 +2256,7 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 		blocksize = root->fs_info->nodesize;
 		eb = btrfs_read_node_slot(upper->eb, slot);
 		if (IS_ERR(eb)) {
-			err = PTR_ERR(eb);
+			ret = PTR_ERR(eb);
 			goto next;
 		}
 		btrfs_tree_lock(eb);
@@ -2273,10 +2266,8 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 					      slot, &eb, BTRFS_NESTING_COW);
 			btrfs_tree_unlock(eb);
 			free_extent_buffer(eb);
-			if (ret < 0) {
-				err = ret;
+			if (ret < 0)
 				goto next;
-			}
 			BUG_ON(node->eb != eb);
 		} else {
 			btrfs_set_node_blockptr(upper->eb, slot,
@@ -2302,19 +2293,19 @@ static int do_relocation(struct btrfs_trans_handle *trans,
 			btrfs_backref_drop_node_buffer(upper);
 		else
 			btrfs_backref_unlock_node_buffer(upper);
-		if (err)
+		if (ret)
 			break;
 	}
 
-	if (!err && node->pending) {
+	if (!ret && node->pending) {
 		btrfs_backref_drop_node_buffer(node);
 		list_move_tail(&node->list, &rc->backref_cache.changed);
 		node->pending = 0;
 	}
 
 	path->lowest_level = 0;
-	BUG_ON(err == -ENOSPC);
-	return err;
+	BUG_ON(ret == -ENOSPC);
+	return ret;
 }
 
 static int link_to_upper(struct btrfs_trans_handle *trans,