metag/uaccess: fix sparse errors

virtio wants to read bitwise types from userspace using get_user.  At the
moment this triggers sparse errors, since the value is passed through an
integer.

Fix that up using __force.

Signed-off-by: Michael S. Tsirkin <mst@redhat.com>
Acked-by: James Hogan <james.hogan@imgtec.com>

arch/metag/include/asm/uaccess.h

@@ -135,7 +135,7 @@ extern long __get_user_bad(void);
 ({                                                              \
 	long __gu_err, __gu_val;                                \
 	__get_user_size(__gu_val, (ptr), (size), __gu_err);	\
-	(x) = (__typeof__(*(ptr)))__gu_val;                     \
+	(x) = (__force __typeof__(*(ptr)))__gu_val;             \
 	__gu_err;                                               \
 })
 
@@ -145,7 +145,7 @@ extern long __get_user_bad(void);
 	const __typeof__(*(ptr)) __user *__gu_addr = (ptr);		\
 	if (access_ok(VERIFY_READ, __gu_addr, size))			\
 		__get_user_size(__gu_val, __gu_addr, (size), __gu_err);	\
-	(x) = (__typeof__(*(ptr)))__gu_val;                             \
+	(x) = (__force __typeof__(*(ptr)))__gu_val;                     \
 	__gu_err;                                                       \
 })