Changes

sctp_server: fix state in catch-all handle_call()

Sending an unexpected call breaks the server, because the third member
of a returned tuple (not_implemented) becomes the new state.  It was
actually meant to be part of the Reply - fix this.

https://www.erlang.org/doc/apps/stdlib/gen_server.html#c:handle_call/3

  {reply, Reply :: term(), NewState :: term()}

Change-Id: I1cc683e549c3bb61e3e4c45bb3d244202d61be53

logging: use ?LOG macros instead of calling logger:level()

The difference between using these macros and the exported functions
is that macros add location (originator) information to the metadata,
and perform lazy evaluation by wrapping the logger call in a case
statement, so it is only evaluated if the log level of the event
passes the primary log level check.

https://www.erlang.org/doc/apps/kernel/logger_chapter.html#logger-api

Change-Id: I3b6e4296f736f9c87d2706ef5fb75146fd9f1239

logging: cosmetic: print mfa at the end of each line

Change-Id: Ib5b8aabd1d7285d22a4cee2beece77691c61f753

logging: convert error_logger:error_report/1 to ?LOG_ERROR

In Erlang/OTP 21.0, a new API for logging was added.  The old error_logger
module can still be used by legacy code, but log events are redirected to
the new Logger API.  New code should use the Logger API directly.

Change-Id: Id6c61fb5ca730209ef625fc5f63d627574e60fbe