virt: acrn: fix a memory leak in acrn_dev_ioctl()

The vm_param and cpu_regs need to be freed via kfree()
before return -EINVAL error.

Fixes: 9c5137aedd11 ("virt: acrn: Introduce VM management interfaces")
Fixes: 2ad2aaee1bc9 ("virt: acrn: Introduce an ioctl to set vCPU registers state")
Signed-off-by: Xiaolong Huang <butterflyhuangxx@gmail.com>
Signed-off-by: Fei Li <fei1.li@intel.com>
Link: https://lore.kernel.org/r/20220308092047.1008409-1-butterflyhuangxx@gmail.com
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
