src/database/sql: run gofmt

Run gofmt on a source file.

Change-Id: I180d5cc7425fc5d8e9cf63005ac692f361beb1ed
Reviewed-on: https://go-review.googlesource.com/c/go/+/508497


Run-TryBot: Than McIntosh <thanm@google.com>
Reviewed-by: Eli Bendersky <eliben@google.com>
TryBot-Result: Gopher Robot <gobot@golang.org>