KVM: x86: popf emulation should not change RF

RFLAGS.RF is always zero after popf. Therefore, popf should not updated RF, as
anyhow emulating popf, just as any other instruction should clear RFLAGS.RF.

Signed-off-by: Nadav Amit <namit@cs.technion.ac.il>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/emulate.c b/arch/x86/kvm/emulate.c
index dd07410..cf117bf 100644
--- a/arch/x86/kvm/emulate.c
+++ b/arch/x86/kvm/emulate.c
@@ -1675,7 +1675,7 @@
 		return rc;
 
 	change_mask = EFLG_CF | EFLG_PF | EFLG_AF | EFLG_ZF | EFLG_SF | EFLG_OF
-		| EFLG_TF | EFLG_DF | EFLG_NT | EFLG_RF | EFLG_AC | EFLG_ID;
+		| EFLG_TF | EFLG_DF | EFLG_NT | EFLG_AC | EFLG_ID;
 
 	switch(ctxt->mode) {
 	case X86EMUL_MODE_PROT64: