PPP: CCP: don't drop output packets if CCP negotiated that we don't compress on our side

CCP might negotiate to not compress if peers cannot agree on a
compressor, therefore if the null compressor is chosen we must pass
packets as is instead of dropping them.

Reported-by: Stephan Linz <linz@li-pro.net>
Fixes: 987f6237c4 "PPP, MPPE, drop input/output packets if we couldn't find the chosen decompressor/compressor"
Signed-off-by: Sylvain Rochet <gradator@gradator.net>

src/include/netif/ppp/ppp.h

@@ -350,8 +350,6 @@ struct ppp_pcb_s {
 #endif /* VJ_SUPPORT */
 #if CCP_SUPPORT
   unsigned int ccp_all_rejected        :1; /* we rejected all peer's options */
-  unsigned int ccp_is_open             :1; /* true when CCP is open (currently negotiating) */
-  unsigned int ccp_is_up               :1; /* true when CCP is up (ready to handle data packets) */
 #endif /* CCP_SUPPORT */
 #if MPPE_SUPPORT
   unsigned int mppe_keys_set           :1; /* Have the MPPE keys been set? */