selftests: kvm: Fix the check of return value

In vm_vcpu_rm() and kvm_vm_release(), a stale return value is checked in
TEST_ASSERT macro.

Fix it by assigning variable ret with correct return value.
Signed-off-by: Zhenzhong Duan <zhenzhong.duan@intel.com>
Message-Id: <20210426193138.118276-1-zhenzhong.duan@intel.com>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>

tools/testing/selftests/kvm/lib/kvm_util.c

@@ -520,7 +520,7 @@ static void vm_vcpu_rm(struct kvm_vm *vm, struct vcpu *vcpu)
 	ret = munmap(vcpu->state, vcpu_mmap_sz());
 	TEST_ASSERT(ret == 0, "munmap of VCPU fd failed, rc: %i "
 		"errno: %i", ret, errno);
-	close(vcpu->fd);
+	ret = close(vcpu->fd);
 	TEST_ASSERT(ret == 0, "Close of VCPU fd failed, rc: %i "
 		"errno: %i", ret, errno);
 
@@ -540,7 +540,7 @@ void kvm_vm_release(struct kvm_vm *vmp)
 	TEST_ASSERT(ret == 0, "Close of vm fd failed,\n"
 		"  vmp->fd: %i rc: %i errno: %i", vmp->fd, ret, errno);
 
-	close(vmp->kvm_fd);
+	ret = close(vmp->kvm_fd);
 	TEST_ASSERT(ret == 0, "Close of /dev/kvm fd failed,\n"
 		"  vmp->kvm_fd: %i rc: %i errno: %i", vmp->kvm_fd, ret, errno);
 }