weston-info: look for the right wp_presentation

Patch b00c79b587a4903df576008a64a49f851fed234c forgot to update the
global interface name to look for. Fix it.

This makes weston-info report the presentation clock again.

Signed-off-by: Pekka Paalanen <pekka.paalanen@collabora.co.uk>
Reviewed-by: Bryce Harrington <bryce@osg.samsung.com>
1 file changed