Fix typos in comments. fixes #24337.

git-svn-id: https://core.svn.wordpress.org/trunk@24255 1a063a9b-81f0-0310-95a4-ce76da25c4cd
RTL: Fix some issues on nav menu screen. see #24326.

git-svn-id: https://core.svn.wordpress.org/trunk@24256 1a063a9b-81f0-0310-95a4-ce76da25c4cd