drm/i915/gvt: fix memory leak in intel_vgpu_ioctl()

The 'sparse' variable may leak when return in function
intel_vgpu_ioctl(), and this patch fix this.
Signed-off-by: Yi Wang <wang.yi59@zte.com.cn>
Reviewed-by: Jiang Biao <jiang.biao2@zte.com.cn>
Signed-off-by: Zhenyu Wang <zhenyuw@linux.intel.com>

drivers/gpu/drm/i915/gvt/kvmgt.c

@@ -1257,11 +1257,13 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
 					&sparse->header, sizeof(*sparse) +
 					(sparse->nr_areas *
 						sizeof(*sparse->areas)));
-				kfree(sparse);
-				if (ret)
+				if (ret) {
+					kfree(sparse);
 					return ret;
+				}
 				break;
 			default:
+				kfree(sparse);
 				return -EINVAL;
 			}
 		}
@@ -1277,6 +1279,7 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
 						  sizeof(info), caps.buf,
 						  caps.size)) {
 					kfree(caps.buf);
+					kfree(sparse);
 					return -EFAULT;
 				}
 				info.cap_offset = sizeof(info);
@@ -1285,6 +1288,7 @@ static long intel_vgpu_ioctl(struct mdev_device *mdev, unsigned int cmd,
 			kfree(caps.buf);
 		}
 
+		kfree(sparse);
 		return copy_to_user((void __user *)arg, &info, minsz) ?
 			-EFAULT : 0;
 	} else if (cmd == VFIO_DEVICE_GET_IRQ_INFO) {