btrfs: remove pointless out labels from ioctl.c

btrfs: remove pointless out labels from ioctl.c

Some functions (__btrfs_ioctl_snap_create(), btrfs_ioctl_subvol_setflags()
and copy_to_sk()) have an 'out' label that does nothing but return, making
it pointless. Simplify this by removing the label and returning instead of
gotos plus setting up the 'ret' variable.

Reviewed-by: Johannes Thumshirn <johannes.thumshirn@wdc.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>