better error message

tools/png2fimg.c

@@ -31,7 +31,7 @@ if (foo) {
 	exit(1);
 	}
 
-fimg_describe(&fimg, "oups");
+fimg_describe(&fimg, argv[2]);
 
 foo = fimg_dump_to_file(&fimg, argv[2], 0);
 fprintf(stderr, "save as fimg -> %d\n", foo);