`$gallery_div` is set twice in `gallery_shortcode()` before it is used.

See #27882.

Built from https://develop.svn.wordpress.org/trunk@28549


git-svn-id: http://core.svn.wordpress.org/trunk@28375 1a063a9b-81f0-0310-95a4-ce76da25c4cd
`$count` is set in `get_post_galleries()` and never used, relic from PFUI RIP.

See #27882.

Built from https://develop.svn.wordpress.org/trunk@28550


git-svn-id: http://core.svn.wordpress.org/trunk@28376 1a063a9b-81f0-0310-95a4-ce76da25c4cd