AX.25 code uses obsolete PF_INET/SOCK_PACKET, gets kernel warnings on some systems.

[tvrusso]

Max Harper reported in 2013 and again last week that his Raspberry Pi install of Xastir results in kernel warnings in /var/log/syslog saying that Xastir uses the obsolete arguments to socket (PF_INET,SOCK_PACKET). These continue to work, but the warnings can be disturbing and also indicate that one day they will stop working.

Chuck Byam had tried to fix this in commit 6085237 back in January of 2003, but there were two problems:

1. The ifdefs he used referenced the incorrect defined constant __GLIBC_MINOR instead of the correct
   __GLIB_MINOR__ and so the code he added was never being compiled
2. The code he had inside that ifdef doesn't work. He used "PF_INET, SOCK_DGRAM". When I fix the ifdef so this is compiled, the system gives invalid argument errors on trying to connect.

I tried to fix it, and even found something that appeared to work (AF_PACKET, SOCK_RAW or AF_PACKET, SOCK_DGRAM), but it turned out my testing was inadequate. I can get Xastir to transmit over AX.25 this way, but it doesn't see any incoming packets. I had initially created a pull request for that fix, but have closed it merged and deleted the branch it referenced (see #20 ).

Someone with better knowledge of AX-25 networking will need to help out on this, because I'm stumped.