My Coccinelle semantic patch finds a few more, because it also fixes up
the equally pointless conditional

    if (foo) {
        free(foo);
        foo = NULL;
    }

Result (feel free to squash it into your patch):

Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Eric Blake <eblake@redhat.com>
Signed-off-by: Michael Tokarev <mjt@tls.msk.ru>