KVM: x86 emulator: Update c->dst.bytes in decode instruction

Update c->dst.bytes in decode instruction instead of instruction
itself.  It's needed because if c->dst.bytes is equal to 0, the
instruction is not emulated.
Signed-off-by: NGuillaume Thouvenin <guillaume.thouvenin@ext.bull.net>
Signed-off-by: NLaurent Vivier <laurent.vivier@bull.net>
Signed-off-by: NAvi Kivity <avi@qumranet.com>

arch/x86/kvm/x86_emulate.c

@@ -1049,6 +1049,7 @@ x86_decode_insn(struct x86_emulate_ctxt *ctxt, struct x86_emulate_ops *ops)
 		break;
 	case DstMem:
 		if ((c->d & ModRM) && c->modrm_mod == 3) {
+			c->dst.bytes = (c->d & ByteOp) ? 1 : c->op_bytes;
 			c->dst.type = OP_REG;
 			c->dst.val = c->dst.orig_val = c->modrm_val;
 			c->dst.ptr = c->modrm_ptr;