checkpath: apply ownership to all paths given on command line

The stat structure was not being initialized correctly in do_check. This
was causing the owner adjustment to be skipped if the first path had the
correct owner.

Also, the "correcting owner" message should always be printed when the
owner is being changed.

X-Gentoo-Bug: 518042
X-Gentoo-Bug-URL: https://bugs.gentoo.org/show_bug.cgi?id=518042