ERR: Remove warnings from tests

Tests/CustomCommand/generator.cxx

@@ -2,6 +2,11 @@
 
 int main(int argc, char *argv[])
 {
+  if ( argc < 2 )
+    {
+    fprintf(stderr, "Usage: %s <file>\n", argv[0]);
+    return 1;
+    }
   FILE *fp = fopen(argv[1],"w");
   
   fprintf(fp,"int generated() { return 3; }\n");

Tests/CustomCommand/wrapper.cxx

@@ -2,6 +2,11 @@
 
 int main(int argc, char *argv[])
 {
+  if ( argc < 2 )
+    {
+    fprintf(stderr, "Usage: %s <file>\n", argv[0]);
+    return 1;
+    }
   FILE *fp = fopen(argv[1],"w");
   
   fprintf(fp,"int wrapped() { return 5; }\n");