In a concurrent removal test, don't remove concurrently with builds

This test is intended to test concurrent removals, so don't
risk a removal breaking a build.

Fixes containers#18659 .

(The sitaution that removals can break a build WIP is a real
problem that should be fixed, but that's not a target of this test.)

Signed-off-by: Miloslav Trmač <mitr@redhat.com>

test/e2e/rmi_test.go

@@ -266,22 +266,33 @@ RUN find $LOCAL
 		podmanTest.AddImageToRWStore(CIRROS_IMAGE)
 		var wg sync.WaitGroup
 
-		buildAndRemove := func(i int) {
-			defer GinkgoRecover()
-			defer wg.Done()
-			imageName := fmt.Sprintf("rmtest:%d", i)
-			containerfile := fmt.Sprintf(`FROM %s
-RUN touch %s`, CIRROS_IMAGE, imageName)
-
-			podmanTest.BuildImage(containerfile, imageName, "false")
-			session := podmanTest.Podman([]string{"rmi", "-f", imageName})
-			session.WaitWithDefaultTimeout()
-			Expect(session).Should(Exit(0))
+		// Prepare images
+		wg.Add(10)
+		for i := 0; i < 10; i++ {
+			go func(i int) {
+				defer GinkgoRecover()
+				defer wg.Done()
+				imageName := fmt.Sprintf("rmtest:%d", i)
+				containerfile := fmt.Sprintf(`FROM %s
+	RUN touch %s`, CIRROS_IMAGE, imageName)
+
+				podmanTest.BuildImage(containerfile, imageName, "false")
+			}(i)
 		}
+		wg.Wait()
 
+		// A herd of concurrent removals
 		wg.Add(10)
 		for i := 0; i < 10; i++ {
-			go buildAndRemove(i)
+			go func(i int) {
+				defer GinkgoRecover()
+				defer wg.Done()
+
+				imageName := fmt.Sprintf("rmtest:%d", i)
+				session := podmanTest.Podman([]string{"rmi", "-f", imageName})
+				session.WaitWithDefaultTimeout()
+				Expect(session).Should(Exit(0))
+			}(i)
 		}
 		wg.Wait()
 	})