KVM: fix fault page leak

fault_page is forgot to be freed
Signed-off-by: NXiao Guangrong <xiaoguangrong@linux.vnet.ibm.com>
Signed-off-by: NMarcelo Tosatti <mtosatti@redhat.com>

virt/kvm/kvm_main.c

@@ -2845,6 +2845,7 @@ void kvm_exit(void)
 	kvm_arch_hardware_unsetup();
 	kvm_arch_exit();
 	free_cpumask_var(cpus_hardware_enabled);
+	__free_page(fault_page);
 	__free_page(hwpoison_page);
 	__free_page(bad_page);
 }