run-tests: use a list comprehension instead of map

tests/run-tests.py

@@ -493,7 +493,7 b' def outputcoverage(options):'
         return
 
     covrun('-c')
-    omit = ','.join(map(os.path.join, [BINDIR, TESTDIR], ['*'] * 2))
+    omit = ','.join(os.path.join(x, '*') for x in [BINDIR, TESTDIR])
     covrun('-i', '-r', '"--omit=%s"' % omit) # report
     if options.annotate:
         adir = os.path.join(TESTDIR, 'annotated')