fix unsafe_put_user()

__put_user_size() relies upon its first argument having the same type as what
the second one points to; the only other user makes sure of that and
unsafe_put_user() should do the same.

Signed-off-by: Al Viro <[e-mail]>

arch/x86/include/asm/uaccess.h

···
 #define unsafe_put_user(x, ptr, err_label)					\
 do {										\
 	int __pu_err;								\
-	__put_user_size((x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT);		\
+	__put_user_size((__typeof__(*(ptr)))(x), (ptr), sizeof(*(ptr)), __pu_err, -EFAULT);		\
 	if (unlikely(__pu_err)) goto err_label;					\
 } while (0)