graphdriver/btrfs: use free wrapper consistently
While the Cgo in this entire file is quite questionable, that is a task
for another day.
@@ -233,7 +233,7 @@ func subvolSnapshot(src, dest, name string) error {
var cs = C.CString(name)
C.set_name_btrfs_ioctl_vol_args_v2(&args, cs)
- C.free(unsafe.Pointer(cs))
+ free(cs)
_, _, errno := unix.Syscall(unix.SYS_IOCTL, getDirFd(destDir), C.BTRFS_IOC_SNAP_CREATE_V2,
uintptr(unsafe.Pointer(&args)))
