Remove comment

Author: tomasr8

Modules/_io/bufferedio.c

@@ -1394,8 +1394,6 @@ _io__Buffered_seek_impl(buffered *self, PyObject *targetobj, int whence)
     if (target == -1 && PyErr_Occurred())
         return NULL;
 
-    // PyNumber_AsOff_t calls user code via __index__, which
-    // could have closed the file.
     CHECK_CLOSED(self, "seek of closed file")
 
     /* SEEK_SET and SEEK_CUR are special because we could seek inside the