Fix compilation error in chan_dahdi (strdupa -> ast_strdupa).

(closes issue #17751)
Reported by: b11d
Patches:
      strdupa_oops.diff uploaded by malcolmd (license 924)


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/1.8@280519 65c4cc65-6c06-0410-ace0-fbb531ad65f3

channels/sig_pri.c

@@ -1746,7 +1746,7 @@ static int sig_pri_msn_match(const char *msn_patterns, const char *exten)
 	char *msn_list;
 	char *list_tail;
 
-	msn_list = strdupa(msn_patterns);
+	msn_list = ast_strdupa(msn_patterns);
 
 	list_tail = NULL;
 	pattern = strtok_r(msn_list, ",", &list_tail);