fsmonitor: drop an unused local variable

Flagged by PyCharm.

Differential Revision: https://phab.mercurial-scm.org/D7752

hgext/fsmonitor/pywatchman/capabilities.py

@@ -62,7 +62,7 b' def synthesize(vers, opts):'
     vers["capabilities"] = {}
     for name in opts["optional"]:
         vers["capabilities"][name] = check(parsed_version, name)
-    failed = False  # noqa: F841 T25377293 Grandfathered in
+
     for name in opts["required"]:
         have = check(parsed_version, name)
         vers["capabilities"][name] = have