tests: fix omit path list

tests: fix omit path list

All directories need a trailing asterisk. Otherwise the files are not excluded
from coverage.

--- a/tests/run-tests.py	Fri Jan 13 14:52:47 2012 +0100
+++ b/tests/run-tests.py	Wed Jan 11 15:37:25 2012 +0100
@@ -493,7 +493,7 @@
         return
 
     covrun('-c')
-    omit = ','.join([BINDIR, TESTDIR])
+    omit = ','.join(map(os.path.join, [BINDIR, TESTDIR], ['*'] * 2))
     covrun('-i', '-r', '"--omit=%s"' % omit) # report
     if options.annotate:
         adir = os.path.join(TESTDIR, 'annotated')