thunderbolt: Fix debug log when DisplayPort adapter not available for pairing

[ Upstream commit 6b8ac54f ]

Fix debug log when looking for a DisplayPort adapter pair of DP IN and
DP OUT. In case of no DP adapter available, log the type of the DP
adapter that is not available.

Signed-off-by: Gil Fine <gil.fine@linux.intel.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Qin Wan <qin.wan@hp.com>
Signed-off-by: Alexandru Gagniuc <alexandru.gagniuc@hp.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>