Fix various mem leaks in the testing code.
Add test_common_cleanup() in test_common.c, to free talloc contexts; call in
test-{helpers,hnbap,ranap}.c. Upon talloc ctx cleanup, ensure that they are
actually empty, in order to catch newly introduced mem leaks.
If non-empty, print talloc context reports.
Change-Id: Ic66c005f2a264774e18bb54e58b87bef5944511c
Fix the ranap_parse_lai() part that decodes the MNC: place the *10 at the
proper MNC digit.
Add a comprehensive test for ranap_parse_lai() in test-helpers.c. Because
ranap_parse_lai() logs things, add test_common.c to test-helpers compilation
and an expected stderr output to test-helpers' testsuite.at def.
A bit hacky: the ranap_ies_defs.h is generated together with the
ranap_encoder.c and ranap_decoder.c. See comments in src/Makefile.am and
include/osmocom/ranap/Makefile.am.