cache_test: TestCallbacks: fix test case

Previously we always tried to create the same key multiple times. This
was problematic because the cache size was 2, so we would never need to
evict a key (we'd never run out of room).

Author: Linus Arver

prow/cache/cache_test.go

@@ -465,15 +465,16 @@ func TestCallbacks(t *testing.T) {
 			cacheCallbacks:    defaultCallbacks,
 			lookups: []lookup{
 				lookup{"(key)1", goodValConstructor},
-				lookup{"(key)1", goodValConstructor},
-				lookup{"(key)1", goodValConstructor},
-				lookup{"(key)1", badValConstructor},
+				lookup{"(key)2", goodValConstructor},
+				lookup{"(key)3", goodValConstructor},
 				lookup{"(key)1", badValConstructor},
+				lookup{"(key)2", badValConstructor},
+				lookup{"(key)3", badValConstructor},
 			},
 			expected: expected{
-				lookups:         5,
+				lookups:         6,
 				hits:            0,
-				misses:          5,
+				misses:          0,
 				forcedEvictions: 0,
 				manualEvictions: 0,
 				// If racyEvictions is true, then we expect some positive number of evictions to occur.