snes: pcx_to_tiles_4bpp

forgot to actually add the command-line parsing code

tb_snes/tools/pcx_to_tiles_4bpp.c

@@ -195,6 +195,11 @@ int main(int argc, char **argv) {
 
     int result;
 
+    /* parse command line args */
+    if (argc>1) {
+       strncpy(label_prefix,argv[1],BUFSIZ);
+    }
+
     /* read from stdin */
 
     result=vmwLoadPCX(fileno(stdin));