Apply suggestions from code review

Co-authored-by: Victor Stinner <vstinner@python.org>

Author: aisk

Lib/test/test_mmap.py

@@ -1171,7 +1171,7 @@ def test_flush_parameters(self):
             if hasattr(mmap, 'MS_ASYNC'):
                 m.flush(flags=mmap.MS_ASYNC)
             if hasattr(mmap, 'MS_INVALIDATE'):
-                m.flush(PAGESIZE * 2, mmap.MS_INVALIDATE)
+                m.flush(PAGESIZE * 2, flags=mmap.MS_INVALIDATE)
             if hasattr(mmap, 'MS_ASYNC') and hasattr(mmap, 'MS_INVALIDATE'):
                 m.flush(0, PAGESIZE, flags=mmap.MS_ASYNC | mmap.MS_INVALIDATE)
     @unittest.skipUnless(sys.platform == 'linux', 'Linux only')

Modules/mmapmodule.c

@@ -1034,6 +1034,7 @@ mmap.mmap.flush
     offset: Py_ssize_t = 0
     size: Py_ssize_t = -1
     /
+    *
     flags: int = 0
 
 [clinic start generated code]*/