[nvptx, libgomp] Update pr85381-{2,4}.c test-cases

[nvptx, libgomp] Update pr85381-{2,4}.c test-cases

After the fix for "PR tree-optimization/89713 - Assume loop with an exit is
finite" ( r272234 ) empty oacc loops are removed before expand.

Update pr85381-{2,4}.c accordingly.

2019-06-15  Tom de Vries  <tdevries@suse.de>

	PR tree-optimization/89713
	* testsuite/libgomp.oacc-c-c++-common/pr85381-2.c: Expect no bar.sync.
	* testsuite/libgomp.oacc-c-c++-common/pr85381-4.c: Same.

git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@272324 138bc75d-0d04-0410-961f-82ee72b054a4