testsuite: Fix pragma-eof.c failure due to added line to the test.

2020-07-18  Jakub Jelinek  <jakub@redhat.com>

	* c-c++-common/cpp/pragma-eof.c: Use .+3 instead of 6 in
	dg-error.

gcc/testsuite/c-c++-common/cpp/pragma-eof.c

@@ -1,7 +1,7 @@
 /* { dg-require-effective-target fopenmp } */
 /* { dg-additional-options -fopenmp }  */
 
-/* { dg-error "expected" "" { target *-*-* } 6 } */
+/* { dg-error "expected" "" { target *-*-* } .+3 } */
 /* Make sure we see pragma_eol even though lacking new line.  *
 /* no newline at end of file.  */
 #pragma omp parallel