Changes

ss7_asp: Update stream_cli read_cb2 functions to accommodate for new API param

libosmo-netif (not yet released) stream_cli osmo_io read_cb API was
updated to provide read result status. Hence, now API users (ss7_asp)
can account for lower layer errors and act properly, like it used to
do with the previous ofd backend.

This commit partially reverts some error code paths removed in
9257cd896e255403822bee6f87f5487a92fd3c11 when converting code to use
osmo_io stream_cli backend.

Change-Id: I579f4101a9e2874e310ff78e4571f38cfe8dfab0
Depends: libosmo-netif.git Change-Id I395c75ff1e9904757ce1d767a9ac2f779593c4c8