virt: acrn: Correct type casting of argument of copy_from_user()

hsm.c:336:50: warning: incorrect type in argument 2 (different address spaces)
hsm.c:336:50:    expected void const [noderef] __user *from
hsm.c:336:50:    got void *

This patch fixes above sparse warning.

Fixes: 3d679d5a ("virt: acrn: Introduce interfaces to query C-states and P-states allowed by hypervisor")
Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: Shuo Liu <shuo.a.liu@intel.com>
Link: https://lore.kernel.org/r/20210310153708.17451-1-shuo.a.liu@intel.comSigned-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/virt/acrn/hsm.c

@@ -333,7 +333,7 @@ static long acrn_dev_ioctl(struct file *filp, unsigned int cmd,
 		acrn_ioreq_request_clear(vm);
 		break;
 	case ACRN_IOCTL_PM_GET_CPU_STATE:
-		if (copy_from_user(&cstate_cmd, (void *)ioctl_param,
+		if (copy_from_user(&cstate_cmd, (void __user *)ioctl_param,
 				   sizeof(cstate_cmd)))
 			return -EFAULT;