btrfs: Ensure the tree search ioctl returns the right number of records

Btrfs's tree search ioctl has a field to indicate that no more than a
given number of records should be returned. The ioctl doesn't honour
this, as the tested value is not incremented until the end of the
copy_to_sk function. This patch removes an unnecessary local variable,
and updates the num_found counter as each key is found in the tree.
Signed-off-by: NHugo Mills <hugo@carfax.org.uk>
Signed-off-by: NChris Mason <chris.mason@oracle.com>

fs/btrfs/ioctl.c

@@ -1279,7 +1279,6 @@ static noinline int copy_to_sk(struct btrfs_root *root,
 	int nritems;
 	int i;
 	int slot;
-	int found = 0;
 	int ret = 0;
 
 	leaf = path->nodes[0];
@@ -1326,7 +1325,7 @@ static noinline int copy_to_sk(struct btrfs_root *root,
 					   item_off, item_len);
 			*sk_offset += item_len;
 		}
-		found++;
+		(*num_found)++;
 
 		if (*num_found >= sk->nr_items)
 			break;
@@ -1345,7 +1344,6 @@ static noinline int copy_to_sk(struct btrfs_root *root,
 	} else
 		ret = 1;
 overflow:
-	*num_found += found;
 	return ret;
 }