KVM: x86/mmu: kvm_faultin_pfn has to return false if pfh is returned

This looks like a typo in 8f32d5e5. This change didn't intend to do
any functional changes.

The problem was caught by gVisor tests.

Fixes: 8f32d5e5 ("KVM: x86/mmu: allow kvm_faultin_pfn to return page fault handling code")
Cc: Maxim Levitsky <mlevitsk@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Signed-off-by: Andrei Vagin <avagin@gmail.com>
Message-Id: <20211015163221.472508-1-avagin@gmail.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

arch/x86/kvm/mmu/mmu.c

@@ -3879,6 +3879,7 @@ static bool kvm_faultin_pfn(struct kvm_vcpu *vcpu, struct kvm_page_fault *fault,
 	fault->pfn = __gfn_to_pfn_memslot(slot, fault->gfn, false, NULL,
 					  fault->write, &fault->map_writable,
 					  &fault->hva);
+	return false;
 
 out_retry:
 	*r = RET_PF_RETRY;