KVM: x86 emulator: simplify OpMem64 decode

Use the same technique as the other OpMem variants, and goto mem_common.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index e46809b..1c95935f 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -3361,11 +3361,7 @@
 		rc = decode_imm(ctxt, op, 1, false);
 		break;
 	case OpMem:
-	case OpMem64:
-		if (d == OpMem64)
-			ctxt->memop.bytes = 8;
-		else
-			ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
+		ctxt->memop.bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;
 	mem_common:
 		*op = ctxt->memop;
 		ctxt->memopp = op;
@@ -3373,6 +3369,9 @@
 			fetch_bit_operand(ctxt);
 		op->orig_val = op->val;
 		break;
+	case OpMem64:
+		ctxt->memop.bytes = 8;
+		goto mem_common;
 	case OpAcc:
 		op->type = OP_REG;
 		op->bytes = (ctxt->d & ByteOp) ? 1 : ctxt->op_bytes;