c++: Return early in apply_late_template_attributes if there are no late attribs...

c++: Return early in apply_late_template_attributes if there are no late attribs [PR101180]

The r12-299-ga0fdff3cf33f7284 change can result in cplus_decl_attributes being called
even if there are no late attributes (but at least one early attribute) in
apply_late_template_attributes.  This patch fixes that, so that we return early
if there are no late attrs, only arrange for TYPE_ATTRIBUTES to get the early
attribute list.

2021-11-25  Jakub Jelinek  <jakub@redhat.com>

	PR c++/101180
	* pt.c (apply_late_template_attributes): Return early if there are no
	dependent attributes.