Remove unused parameters from test code.

test/include_dirs/src/subdir/subdir_includes.c

 #include <stdio.h>
 
 #include "inc.h"
 #include "include1.h"
 #include "include2.h"
 
-int main(int argc, char *argv[])
+int main(void)
 {
   printf("Hello from subdir/subdir_includes.c\n");
   printf("Hello from %s\n", INC_STRING);
   printf("Hello from %s\n", INCLUDE1_STRING);
   printf("Hello from %s\n", INCLUDE2_STRING);
   return 0;
 }