KVM: x86: merge handle_mmio_page_fault and handle_mmio_page_fault_common

They are exactly the same, except that handle_mmio_page_fault
has an unused argument and a call to WARN_ON.  Remove the unused
argument from the callers, and move the warning to (the former)
handle_mmio_page_fault_common.

Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index 5eb56ed..a26ed28 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -5908,7 +5908,7 @@
 		return 1;
 	}
 
-	ret = handle_mmio_page_fault_common(vcpu, gpa, true);
+	ret = handle_mmio_page_fault(vcpu, gpa, true);
 	if (likely(ret == RET_MMIO_PF_EMULATE))
 		return x86_emulate_instruction(vcpu, gpa, 0, NULL, 0) ==
 					      EMULATE_DONE;