Twenty Fourteen: Correct $query usage in Featured_Content::pre_get_posts()

[SergeyBiryukov]

Background: [26189] (which should have had a ticket).

Featured_Content::pre_get_posts() has some issues:

1. No need to set the default $query value to false. The method is hooked to pre_get_posts action and is not called separately, so a WP_Query object is always passed.
2. The is_a( $query, 'WP_Query' ) check is redundant for the same reason.
3. $query->is_home() method should be used instead of the is_home() template tag. Before [26189], this was causing a _doing_it_wrong() notice in unit tests. [26189] avoided the notice by moving is_home() to the end of the condition. I guess using $query->is_home() would be the more correct fix.

[lancewillett]

Thank you for the ticket and updated fix, I was going to ask for a longer explanation anyway. :)

[lancewillett]

In 26255:

Twenty Fourteen: correct $query usage in Featured_Content::pre_get_posts(), props SergeyBiryukov, fixes #26064.

[SergeyBiryukov]

In 26257:

Correctly capitalize WP_Query in Featured_Content::pre_get_posts() inline docs. see #26064.