remove redundant null check. Found by Klockwork (www.klocwork.com)

git-svn-id: http://svn.freeswitch.org/svn/freeswitch/trunk@8444 d0543943-73ff-0310-b7d9-9358b9ac24b2

src/switch_event.c

@@ -790,7 +790,7 @@ SWITCH_DECLARE(switch_status_t) switch_event_serialize(switch_event_t *event, ch
 			}
 		}
 
-		switch_snprintf(buf + len, dlen - len, "%s: %s\n", hp->name, switch_strlen_zero(encode_buf) ? "_undef_" : encode_buf);
+		switch_snprintf(buf + len, dlen - len, "%s: %s\n", hp->name, *encode_buf == '\0' ? "_undef_" : encode_buf);
 		len = strlen(buf);
 	}