src, misc: applied gofmt -s -w

Pending CL 113120043.

LGTM=dave
R=golang-codereviews, dave
CC=golang-codereviews
https://golang.org/cl/112290043

src/pkg/database/sql/sql.go

@@ -580,7 +580,7 @@ func (db *DB) maybeOpenNewConnections() {
 
 // Runs in a separate goroutine, opens new connections when requested.
 func (db *DB) connectionOpener() {
-	for _ = range db.openerCh {
+	for range db.openerCh {
 		db.openNewConnection()
 	}
 }