revert clicompat-r2.patch from r401704

Patch caused the following build errors against testsuite
https://bamboo.asterisk.org/bamboo/browse/AST-ATRUNKBUILD4-244

(issue ASTERISK-22467)
Reported by: Corey Farrell
........

Merged revisions 401895 from http://svn.asterisk.org/svn/asterisk/branches/1.8


git-svn-id: https://origsvn.digium.com/svn/asterisk/branches/11@401896 65c4cc65-6c06-0410-ace0-fbb531ad65f3

utils/clicompat.c

@@ -9,18 +9,8 @@ void ast_cli(int fd, const char *fmt, ...)
 
 struct ast_cli_entry;
 
-int ast_register_atexit(void (*func)(void));
-int ast_register_atexit(void (*func)(void))
-{
-	return 0;
-}
 int ast_cli_register_multiple(struct ast_cli_entry *e, int len);
 int ast_cli_register_multiple(struct ast_cli_entry *e, int len)
 {
 	return 0;
 }
-int ast_cli_unregister_multiple(struct ast_cli_entry *e, int len);
-int ast_cli_unregister_multiple(struct ast_cli_entry *e, int len)
-{
-	return 0;
-}