KVM: x86 emulator: fix Src2CL decode

Src2CL decode (used for double width shifts) erronously decodes only bit 3
of %rcx, instead of bits 7:0.

Fix by decoding %cl in its entirety.

Signed-off-by: Avi Kivity <avi@redhat.com>
Signed-off-by: Marcelo Tosatti <mtosatti@redhat.com>

arch/x86/kvm/emulate.c

@@ -3603,7 +3603,7 @@ done_prefixes:
 		break;
 	case Src2CL:
 		ctxt->src2.bytes = 1;
-		ctxt->src2.val = ctxt->regs[VCPU_REGS_RCX] & 0x8;
+		ctxt->src2.val = ctxt->regs[VCPU_REGS_RCX] & 0xff;
 		break;
 	case Src2ImmByte:
 		rc = decode_imm(ctxt, &ctxt->src2, 1, true);