sparc64/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: David S. Miller <davem@davemloft.net>

arch/sparc/include/asm/uaccess_64.h

@@ -145,7 +145,7 @@ case 2: __get_user_asm(__gu_val,uh,addr,__gu_ret); break; \
 case 4: __get_user_asm(__gu_val,uw,addr,__gu_ret); break; \
 case 8: __get_user_asm(__gu_val,x,addr,__gu_ret); break; \
 default: __gu_val = 0; __gu_ret = __get_user_bad(); break; \
-} data = (type) __gu_val; __gu_ret; })
+} data = (__force type) __gu_val; __gu_ret; })
 
 #define __get_user_nocheck_ret(data,addr,size,type,retval) ({ \
 register unsigned long __gu_val __asm__ ("l1"); \
@@ -155,7 +155,7 @@ case 2: __get_user_asm_ret(__gu_val,uh,addr,retval); break; \
 case 4: __get_user_asm_ret(__gu_val,uw,addr,retval); break; \
 case 8: __get_user_asm_ret(__gu_val,x,addr,retval); break; \
 default: if (__get_user_bad()) return retval; \
-} data = (type) __gu_val; })
+} data = (__force type) __gu_val; })
 
 #define __get_user_asm(x,size,addr,ret)					\
 __asm__ __volatile__(							\