Fix unused-result errors on import.

test/cpp/end2end/xds_end2end_test.cc

@@ -1501,7 +1501,7 @@ using LdsTest = BasicTest;
 TEST_P(LdsTest, Vanilla) {
   SetNextResolution({});
   SetNextResolutionForLbChannelAllBalancers();
-  SendRpc();
+  (void)SendRpc();
   EXPECT_EQ(balancers_[0]->ads_service()->lds_response_state(),
             AdsServiceImpl::ACKED);
 }
@@ -1571,7 +1571,7 @@ TEST_P(LdsTest, ChooseMatchedDomain) {
         AdsServiceImpl::BuildListener(route_config)}});
   SetNextResolution({});
   SetNextResolutionForLbChannelAllBalancers();
-  SendRpc();
+  (void)SendRpc();
   EXPECT_EQ(balancers_[0]->ads_service()->lds_response_state(),
             AdsServiceImpl::ACKED);
 }
@@ -1592,7 +1592,7 @@ TEST_P(LdsTest, ChooseLastRoute) {
         AdsServiceImpl::BuildListener(route_config)}});
   SetNextResolution({});
   SetNextResolutionForLbChannelAllBalancers();
-  SendRpc();
+  (void)SendRpc();
   EXPECT_EQ(balancers_[0]->ads_service()->lds_response_state(),
             AdsServiceImpl::ACKED);
 }
@@ -1667,7 +1667,7 @@ TEST_P(RdsTest, Vanilla) {
   balancers_[0]->ads_service()->SetLdsToUseDynamicRds();
   SetNextResolution({});
   SetNextResolutionForLbChannelAllBalancers();
-  SendRpc();
+  (void)SendRpc();
   EXPECT_EQ(balancers_[0]->ads_service()->rds_response_state(),
             AdsServiceImpl::ACKED);
 }
@@ -1706,7 +1706,7 @@ TEST_P(RdsTest, ChooseMatchedDomain) {
       {{"application_target_name", std::move(route_config)}});
   SetNextResolution({});
   SetNextResolutionForLbChannelAllBalancers();
-  SendRpc();
+  (void)SendRpc();
   EXPECT_EQ(balancers_[0]->ads_service()->rds_response_state(),
             AdsServiceImpl::ACKED);
 }
@@ -1727,7 +1727,7 @@ TEST_P(RdsTest, ChooseLastRoute) {
       {{"application_target_name", std::move(route_config)}});
   SetNextResolution({});
   SetNextResolutionForLbChannelAllBalancers();
-  SendRpc();
+  (void)SendRpc();
   EXPECT_EQ(balancers_[0]->ads_service()->rds_response_state(),
             AdsServiceImpl::ACKED);
 }
@@ -1802,7 +1802,7 @@ using CdsTest = BasicTest;
 TEST_P(CdsTest, Vanilla) {
   SetNextResolution({});
   SetNextResolutionForLbChannelAllBalancers();
-  SendRpc();
+  (void)SendRpc();
   EXPECT_EQ(balancers_[0]->ads_service()->cds_response_state(),
             AdsServiceImpl::ACKED);
 }