script: jtag_autoinit returns success, count via last_data_value

It returned the loaded-BSDL count, which the engine flagged as an error
code ("Command failed with code: 1") whenever a BSDL matched. Stash the
count in last_data_value and return JTAG_CORE_NO_ERROR instead.

modules/script/script.c

@@ -1575,7 +1575,10 @@ static int cmd_autoinit(script_ctx *ctx, char *line)
         return JTAG_CORE_ACCESS_ERROR;
     }
 
-    return loaded_bsdl;
+    // Expose the count to scripts via last_data_value, but report success
+    // (a non-zero return is treated as an error code by the engine).
+    ctx->last_data_value = loaded_bsdl;
+    return JTAG_CORE_NO_ERROR;
 }
 
 const char *cmd_init_and_scan_help[] = {