warnless: remove curlx_ultosi

... not used anywhere

Closes #6530

lib/warnless.c

@@ -5,7 +5,7 @@
  *                            | (__| |_| |  _ <| |___
  *                             \___|\___/|_| \_\_____|
  *
- * Copyright (C) 1998 - 2020, Daniel Stenberg, <daniel@haxx.se>, et al.
+ * Copyright (C) 1998 - 2021, Daniel Stenberg, <daniel@haxx.se>, et al.
  *
  * This software is licensed as described in the file COPYING, which
  * you should have received as part of this distribution. The terms
@@ -155,25 +155,6 @@ unsigned char curlx_ultouc(unsigned long ulnum)
 #endif
 }
 
-/*
-** unsigned long to signed int
-*/
-
-int curlx_ultosi(unsigned long ulnum)
-{
-#ifdef __INTEL_COMPILER
-#  pragma warning(push)
-#  pragma warning(disable:810) /* conversion may lose significant bits */
-#endif
-
-  DEBUGASSERT(ulnum <= (unsigned long) CURL_MASK_SINT);
-  return (int)(ulnum & (unsigned long) CURL_MASK_SINT);
-
-#ifdef __INTEL_COMPILER
-#  pragma warning(pop)
-#endif
-}
-
 /*
 ** unsigned size_t to signed curl_off_t
 */