Merge pull request ARMmbed#12263 from maciejbocianski/fix_unittests_coverage_filtering

unittest: fix coverage filtering

Author: 0xc0170

UNITTESTS/unit_test/coverage.py

@@ -83,7 +83,7 @@ def _gen_cmd(self, coverage_type, excludes, filter_regex):
             filters = filter_regex.split(",")
 
             for filt in filters:
-                regex = "(.+/)?%s" % filt.replace("-", "/")
+                regex = "(.+/)?.*%s" % filt.replace("-", "/")
                 args.extend(["-f", regex])
 
         if logging.getLogger().getEffectiveLevel() == logging.DEBUG: