Clean and simplify some code (#279)

* Clean and simplify some code

Signed-off-by: JmPotato <ghzpotato@gmail.com>

* Remove unused Makefile content

Signed-off-by: JmPotato <ghzpotato@gmail.com>

Makefile

@@ -2,8 +2,6 @@ BRANCH=`git rev-parse --abbrev-ref HEAD`
 COMMIT=`git rev-parse --short HEAD`
 GOLDFLAGS="-X main.branch $(BRANCH) -X main.commit $(COMMIT)"
 
-default: build
-
 race:
 	@TEST_FREELIST_TYPE=hashmap go test -v -race -test.run="TestSimulate_(100op|1000op)"
 	@echo "array freelist test"

db_test.go

@@ -395,7 +395,7 @@ func TestOpen_FileTooSmall(t *testing.T) {
 		t.Fatal(err)
 	}
 
-	db, err = bolt.Open(path, 0666, nil)
+	_, err = bolt.Open(path, 0666, nil)
 	if err == nil || err.Error() != "file size too small" {
 		t.Fatalf("unexpected error: %s", err)
 	}

tx_test.go

@@ -45,8 +45,7 @@ func TestTx_Check_ReadOnly(t *testing.T) {
 	numChecks := 2
 	errc := make(chan error, numChecks)
 	check := func() {
-		err, _ := <-tx.Check()
-		errc <- err
+		errc <- <-tx.Check()
 	}
 	// Ensure the freelist is not reloaded and does not race.
 	for i := 0; i < numChecks; i++ {