Changes

improve HNBAP error logging

We have a situation where HNBAP is not answered by osmo-hnbgw, and the
log is all silent. Add logging to a lot more of the possible HNBAP
failure paths to find out what is wrong.

Related: SYS#6810
Change-Id: I17d2809f59087d32e7c11a3ada1d3fadf6f0b660