Fix hook name in LsofFdLeakChecker

Author: nicoddemus

_pytest/pytester.py

@@ -88,7 +88,7 @@ def matching_platform(self):
             return True
 
     @pytest.hookimpl(hookwrapper=True, tryfirst=True)
-    def pytest_runtest_item(self, item):
+    def pytest_runtest_protocol(self, item):
         lines1 = self.get_open_files()
         yield
         if hasattr(sys, "pypy_version_info"):