按提示词结论修正 RTAPI shim 源码依据

core/wasm_shims/rtapi_compat.cc

@@ -1,8 +1,8 @@
 #include <cstdarg>
 #include <cstdio>
 
-// LinuxCNC source basis: src/rtapi/rtai_rtapi.c provides rtapi_snprintf()
-// for RTAPI-compatible formatting call sites.
+// LinuxCNC source basis: src/rtapi/uspace_common.h provides rtapi_snprintf()
+// for userspace RTAPI formatting; src/rtapi/rtapi.h declares the API.
 extern "C" int rtapi_snprintf(char *buf, unsigned long size, const char *fmt, ...) {
     va_list ap;
     va_start(ap, fmt);