btrfs: return early from failed memory allocations in ioctl handlers

There is no need to call kfree() if memdup_user() fails, as no memory
was allocated and the error in the error-valued pointer should be returned.
Signed-off-by: NShailendra Verma <shailendra.v@samsung.com>
[ edit subject ]
Signed-off-by: NDavid Sterba <dsterba@suse.com>

fs/btrfs/ioctl.c

@@ -4569,11 +4569,8 @@ static long btrfs_ioctl_logical_to_ino(struct btrfs_root *root,
 		return -EPERM;
 
 	loi = memdup_user(arg, sizeof(*loi));
-	if (IS_ERR(loi)) {
-		ret = PTR_ERR(loi);
-		loi = NULL;
-		goto out;
-	}
+	if (IS_ERR(loi))
+		return PTR_ERR(loi);
 
 	path = btrfs_alloc_path();
 	if (!path) {
@@ -5200,11 +5197,8 @@ static long btrfs_ioctl_set_received_subvol_32(struct file *file,
 	int ret = 0;
 
 	args32 = memdup_user(arg, sizeof(*args32));
-	if (IS_ERR(args32)) {
-		ret = PTR_ERR(args32);
-		args32 = NULL;
-		goto out;
-	}
+	if (IS_ERR(args32))
+		return PTR_ERR(args32);
 
 	args64 = kmalloc(sizeof(*args64), GFP_KERNEL);
 	if (!args64) {
@@ -5252,11 +5246,8 @@ static long btrfs_ioctl_set_received_subvol(struct file *file,
 	int ret = 0;
 
 	sa = memdup_user(arg, sizeof(*sa));
-	if (IS_ERR(sa)) {
-		ret = PTR_ERR(sa);
-		sa = NULL;
-		goto out;
-	}
+	if (IS_ERR(sa))
+		return PTR_ERR(sa);
 
 	ret = _btrfs_ioctl_set_received_subvol(file, sa);