[PATCH 4.15 049/122] ppp: prevent unregistered channels from connecting to PPP units

4.15-stable review patch. If anyone has any objections, please let me know. -- From: Guillaume Nault [ Upstream commit 77f840e3e5f09c6d7d727e85e6e08276dd813d11 ] PPP units don't hold any reference on the channels connected to it. It is the channel's

[PATCH 4.15 049/122] ppp: prevent unregistered channels from connecting to PPP units

4.15-stable review patch. If anyone has any objections, please let me know. -- From: Guillaume Nault [ Upstream commit 77f840e3e5f09c6d7d727e85e6e08276dd813d11 ] PPP units don't hold any reference on the channels connected to it. It is the channel's responsibility to ensure