Simplify builder TestTestData slightly by using ioutil.ReadFile instead of os.Open+ioutil.ReadAll

Signed-off-by: Andrew "Tianon" Page <admwiggin@gmail.com>

builder/parser/parser_test.go

@@ -54,18 +54,14 @@ func TestTestData(t *testing.T) {
 		if err != nil {
 			t.Fatalf("Dockerfile missing for %s: %s", dir.Name(), err.Error())
 		}
-
-		rf, err := os.Open(resultfile)
-		if err != nil {
-			t.Fatalf("Result file missing for %s: %s", dir.Name(), err.Error())
-		}
+		defer df.Close()
 
 		ast, err := Parse(df)
 		if err != nil {
 			t.Fatalf("Error parsing %s's dockerfile: %s", dir.Name(), err.Error())
 		}
 
-		content, err := ioutil.ReadAll(rf)
+		content, err := ioutil.ReadFile(resultfile)
 		if err != nil {
 			t.Fatalf("Error reading %s's result file: %s", dir.Name(), err.Error())
 		}
@@ -75,8 +71,5 @@ func TestTestData(t *testing.T) {
 			fmt.Fprintln(os.Stderr, "Expected:\n"+string(content))
 			t.Fatalf("%s: AST dump of dockerfile does not match result", dir.Name())
 		}
-
-		df.Close()
-		rf.Close()
 	}
 }