KVM: nVMX: kmap() can't fail

BugLink: http://bugs.launchpad.net/bugs/1756866

commit 42cf014d upstream.

kmap() can't fail, therefore it will always return a valid pointer. Let's
just get rid of the unnecessary checks.
Signed-off-by: David Hildenbrand <david@redhat.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
[jwang: port to 4.4]
Signed-off-by: Jack Wang <jinpu.wang@profitbricks.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Stefan Bader <stefan.bader@canonical.com>

arch/x86/kvm/vmx.c

@@ -4552,10 +4552,6 @@ static int vmx_complete_nested_posted_interrupt(struct kvm_vcpu *vcpu)
 			return 0;
 
 		vapic_page = kmap(vmx->nested.virtual_apic_page);
-		if (!vapic_page) {
-			WARN_ON(1);
-			return -ENOMEM;
-		}
 		__kvm_apic_update_irr(vmx->nested.pi_desc->pir, vapic_page);
 		kunmap(vmx->nested.virtual_apic_page);
 
@@ -9256,11 +9252,6 @@ static inline bool nested_vmx_merge_msr_bitmap(struct kvm_vcpu *vcpu,
 		return false;
 	}
 	msr_bitmap = (unsigned long *)kmap(page);
-	if (!msr_bitmap) {
-		nested_release_page_clean(page);
-		WARN_ON(1);
-		return false;
-	}
 
 	if (nested_cpu_has_virt_x2apic_mode(vmcs12)) {
 		if (nested_cpu_has_apic_reg_virt(vmcs12))