Stop spamming for wait channel acquirement in orderer integration test

The code passes a function that returns a channel instead of the channel returned by that function.
As a result, the function is being polled thousands of times needlessly and thousands of channels
are being created, after which a goroutine per channel feeds a value into each of them.

Unfortunately, Gomega uses reflection based select on each of these channels, which is non-blocking,
meaning it just grabs a lock on the channel, and if the sender goroutine hasn't sent the item yet,
it returns false.

Since we pass in the Gomega.Eventually, a function (and not a channel), the reflection based receive is only attempted
once on each channel (out of the thousands created) and this creates a flake, because sometimes
we reach the timeout before one of the goroutines has a chance to obtain the lock on the channel
before the reflection based select obtains it, sees the channel buffer is empty, and the Gomega
attempt for that channel is then given up.

Change-Id: I4417703d17e48afec50f46f3ae6b77a8e61a9be7
Signed-off-by: Yacov Manevich <yacovm@il.ibm.com>

integration/raft/config_test.go

@@ -162,7 +162,7 @@ var _ = Describe("EndToEnd reconfiguration and onboarding", func() {
 			By("Starting orderer with malformed genesis block")
 			ordererRunner := network.OrdererGroupRunner()
 			process := ifrit.Invoke(ordererRunner)
-			Eventually(process.Wait, network.EventuallyTimeout).Should(Receive()) // orderer process should exit
+			Eventually(process.Wait(), network.EventuallyTimeout).Should(Receive()) // orderer process should exit
 			network.Cleanup()
 			os.RemoveAll(testDir)
 
@@ -208,7 +208,7 @@ var _ = Describe("EndToEnd reconfiguration and onboarding", func() {
 
 			exitCode := network.CreateChannelExitCode(channel, orderer, org1Peer0, org1Peer0, org2Peer0, orderer)
 			Expect(exitCode).NotTo(Equal(0))
-			Consistently(process.Wait).ShouldNot(Receive()) // malformed tx should not crash orderer
+			Consistently(process.Wait()).ShouldNot(Receive()) // malformed tx should not crash orderer
 			Expect(runner.Err()).To(gbytes.Say(`invalid new config metadata: ElectionTick \(10\) must be greater than HeartbeatTick \(10\)`))
 
 			By("Submitting channel config update with illegal value")