kvprober: remove unnecessary checks to avoid flakes

This commit removes two unnecessary checks, to avoid flakes. The removed checks
can cause flakes, since they require all probes (of a certain type) to fail,
even tho the test server is not configured to fail probes until after server
startup. That is, there is a race condition. The checks are also unnecessary.
What we really care about is the checks that follow the deleted ones: That
the ten probes run within test all fail, since those happen after the test
server is configured to fail probes.

Release note: None.
Epic: None.

Author: joshimhoff

pkg/kv/kvprober/kvprober_integration_test.go

@@ -171,8 +171,6 @@ func TestProberDoesReadsAndWrites(t *testing.T) {
 			p.WriteProbe(ctx, s.DB())
 		}
 
-		// Expect all read probes to fail but write probes & planning to succeed.
-		require.Equal(t, p.Metrics().ReadProbeAttempts.Count(), p.Metrics().ReadProbeFailures.Count())
 		// kvprober is running in background, so more than ten probes may be run.
 		require.GreaterOrEqual(t, p.Metrics().ReadProbeFailures.Count(), int64(10))
 
@@ -220,8 +218,6 @@ func TestProberDoesReadsAndWrites(t *testing.T) {
 			p.WriteProbe(ctx, s.DB())
 		}
 
-		// Expect all write probes to fail but read probes & planning to succeed.
-		require.Equal(t, p.Metrics().WriteProbeAttempts.Count(), p.Metrics().WriteProbeFailures.Count())
 		// kvprober is running in background, so more than ten probes may be run.
 		require.GreaterOrEqual(t, p.Metrics().WriteProbeFailures.Count(), int64(10))