x86/sev: Fix noinstr for vc_ghcb_invalidate()

vmlinux.o: warning: objtool: __sev_put_ghcb()+0x88: call to __memset() leaves .noinstr.text section
vmlinux.o: warning: objtool: __sev_es_nmi_complete()+0x39: call to __memset() leaves .noinstr.text section
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Link: https://lore.kernel.org/r/20210624095148.250770465@infradead.org

arch/x86/kernel/sev-shared.c

@@ -64,7 +64,7 @@ static bool sev_es_negotiate_protocol(void)
 static __always_inline void vc_ghcb_invalidate(struct ghcb *ghcb)
 {
 	ghcb->save.sw_exit_code = 0;
-	memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
+	__builtin_memset(ghcb->save.valid_bitmap, 0, sizeof(ghcb->save.valid_bitmap));
 }
 
 static bool vc_decoding_needed(unsigned long exit_code)