fix spandsp for windows build

libs/spandsp/src/fax_modems.c

@@ -152,7 +152,7 @@ SPAN_DECLARE(const char *) fax_modem_to_str(int modem)
 /*- End of function --------------------------------------------------------*/
 
 //static void fax_modems_hdlc_accept(void *user_data, const uint8_t *msg, int len, int ok)
-SPAN_DECLARE(void) fax_modems_hdlc_accept(void *user_data, const uint8_t *msg, int len, int ok)
+SPAN_DECLARE_NONSTD(void) fax_modems_hdlc_accept(void *user_data, const uint8_t *msg, int len, int ok)
 {
     fax_modems_state_t *s;
 

libs/spandsp/src/spandsp/fax_modems.h

@@ -59,7 +59,7 @@ extern "C"
 {
 #endif
 
-SPAN_DECLARE(void) fax_modems_hdlc_accept(void *user_data, const uint8_t *msg, int len, int ok);
+SPAN_DECLARE_NONSTD(void) fax_modems_hdlc_accept(void *user_data, const uint8_t *msg, int len, int ok);
 
 /*! Convert a FAX modem type to a short text description.
     \brief Convert a FAX modem type to a short text description.