Fix testcases for PR c/78304

The testcases as written made assumptions about size_t and long
being invalid for use with "%u".

We only need some invalid type, so this patch converts them to
attempt a "const char *" with "%u", which should be invalid for
every target.

gcc/testsuite/ChangeLog:
	PR c/78304
	* gcc.dg/format/pr78304.c: Convert argument from integral type
	to a pointer.
	* gcc.dg/format/pr78304-2.c: Likewise.

From-SVN: r244502

gcc/testsuite/ChangeLog

+2017-01-16  David Malcolm  <dmalcolm@redhat.com>
+
+	PR c/78304
+	* gcc.dg/format/pr78304.c: Convert argument from integral type
+	to a pointer.
+	* gcc.dg/format/pr78304-2.c: Likewise.
+
 2017-01-16  Carl Love  <cel@us.ibm.com>
 
 	* gcc.target/powerpc/builtins-3.c: New vec_nabs testcase.

gcc/testsuite/gcc.dg/format/pr78304-2.c

@@ -5,7 +5,7 @@ extern int printf (const char *, ...);
 
 # define PRIu32		"u"
 
-void test (long size)
+void test (const char *msg)
 {
-  printf ("size: %" PRIu32 "\n", size); /* { dg-warning "expects argument of type" } */
+  printf ("size: %" PRIu32 "\n", msg); /* { dg-warning "expects argument of type" } */
 }

gcc/testsuite/gcc.dg/format/pr78304.c

@@ -4,7 +4,7 @@
 #include <inttypes.h>
 #include <stdio.h>
 
-void test (size_t size)
+void test (const char *msg)
 {
-  printf ("size: %" PRIu32 "\n", size); /* { dg-warning "expects argument of type" } */
+  printf ("size: %" PRIu32 "\n", msg); /* { dg-warning "expects argument of type" } */
 }