avocado/core/loader.py: remove "FILTERED" type

This test type (discovery status, really), has never been used.  Even
though there's been work on filtering tests (by tags), this doesn't
really apply to that work at this point.
Signed-off-by: NCleber Rosa <crosa@redhat.com>

avocado/core/loader.py

@@ -354,13 +354,6 @@ class AccessDeniedPath(object):
     pass
 
 
-class FilteredOut(object):
-
-    """ Dummy object to represent test filtered out by the optional mask """
-
-    pass
-
-
 def add_loader_options(parser):
     arggrp = parser.add_argument_group('loader options')
     arggrp.add_argument('--loaders', nargs='*', help="Overrides the priority "
@@ -420,8 +413,7 @@ class FileLoader(TestLoader):
                 test.MissingTest: 'MISSING',
                 BrokenSymlink: 'BROKEN_SYMLINK',
                 AccessDeniedPath: 'ACCESS_DENIED',
-                test.Test: 'INSTRUMENTED',
-                FilteredOut: 'FILTERED'}
+                test.Test: 'INSTRUMENTED'}
 
     @staticmethod
     def get_decorator_mapping():
@@ -430,8 +422,7 @@ class FileLoader(TestLoader):
                 test.MissingTest: output.TERM_SUPPORT.fail_header_str,
                 BrokenSymlink: output.TERM_SUPPORT.fail_header_str,
                 AccessDeniedPath: output.TERM_SUPPORT.fail_header_str,
-                test.Test: output.TERM_SUPPORT.healthy_str,
-                FilteredOut: output.TERM_SUPPORT.warn_header_str}
+                test.Test: output.TERM_SUPPORT.healthy_str}
 
     def discover(self, reference, which_tests=DEFAULT):
         """