KVM: x86 emulator: Re-add VendorSpecific tag to VMMCALL insn

VMMCALL needs the VendorSpecific tag so that #UD emulation
(called if a guest running on AMD was migrated to an Intel host)
is allowed to process the instruction.
Signed-off-by: Avi Kivity <avi@redhat.com>

arch/x86/kvm/emulate.c

@@ -2677,7 +2677,7 @@ static struct opcode group7_rm1[] = {
 
 static struct opcode group7_rm3[] = {
 	DIP(SrcNone | ModRM | Prot | Priv, vmrun,   check_svme_pa),
-	DIP(SrcNone | ModRM | Prot       , vmmcall, check_svme),
+	DIP(SrcNone | ModRM | Prot | VendorSpecific, vmmcall, check_svme),
 	DIP(SrcNone | ModRM | Prot | Priv, vmload,  check_svme_pa),
 	DIP(SrcNone | ModRM | Prot | Priv, vmsave,  check_svme_pa),
 	DIP(SrcNone | ModRM | Prot | Priv, stgi,    check_svme),