Add description comment for find_login_id()

src/sbbs3/userdat.c

@@ -151,6 +151,9 @@ bool matchusername(scfg_t* cfg, const char* name, const char* comp)
 	return *np == '\0' && (*cp == '\0' || *cp == '@');
 }
 
+/****************************************************************************/
+// Given a login-ID (user number, alias, or real name), return the user
+// number or 0 on failure
 /****************************************************************************/
 uint find_login_id(scfg_t* cfg, const char* user_id)
 {