log: change 'log_all_origins' from bool to a list of levels to apply to

The idea is to see the full origin list for log level ERR, while the rest
of the logging can be kept less verbose.

Change-Id: I0277782652548fa321f767da79b207d70678fad1
diff --git a/src/osmo-gsm-tester.py b/src/osmo-gsm-tester.py
index 9b7ae25..53a1dab 100755
--- a/src/osmo-gsm-tester.py
+++ b/src/osmo-gsm-tester.py
@@ -129,7 +129,7 @@
     print('tests:', repr(args.test))
 
     # create a default log to stdout
-    log.LogTarget().style(all_origins=False, src=False)
+    log.LogTarget().style(all_origins_on_levels=(log.L_ERR, log.L_TRACEBACK), src=False)
 
     if args.log_level:
         log.set_all_levels(log.LEVEL_STRS.get(args.log_level))