tm: _strnstr() moved to core

modules/tm/t_msgbuilder.c

@@ -1456,29 +1456,6 @@ static inline char* print_callid(char* w, dlg_t* dialog, struct cell* t)
 	return w;
 }
 
-/*
-* Find the first occurrence of find in s, where the search is limited to the
-* first slen characters of s.
-*/
-static
-char * _strnstr(const char* s, const char* find, size_t slen) {
-	char c, sc;
-	size_t len;
-
-	if ((c = *find++) != '\0') {
-		len = strlen(find);
-		do {
-			do {
-				if (slen-- < 1 || (sc = *s++) == '\0')
-					return (NULL);
-			} while (sc != c);
-			if (len > slen)
-				return (NULL);
-		} while (strncmp(s, find, len) != 0);
-		s--;
-	}
-	return ((char *)s);
-}
 
 /*
  * Create a request