thunderbolt: Show key using %*pE not %*pEp

%*pEp (without "h" or "o") is a no-op.  This string could contain
arbitrary (non-NULL) characters, so we do want escaping.  Use %*pE like
every other caller.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>