KVM: x86 emulator: do not adjust the address for immediate source

adjust the dst address for a register source but not adjust the
address for an immediate source.

Signed-off-by: Wei Yongjun <yjwei@cn.fujitsu.com>
Reviewed-by: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/emulate.c

@@ -727,7 +727,7 @@ static void fetch_bit_operand(struct decode_cache *c)
 {
 	long sv, mask;
 
-	if (c->dst.type == OP_MEM) {
+	if (c->dst.type == OP_MEM && c->src.type == OP_REG) {
 		mask = ~(c->dst.bytes * 8 - 1);
 
 		if (c->src.bytes == 2)