py: unittests: Fix selector fd use

pyright complains about passing fileobj to os.read. Indeed, the
parameter should be an int, but I guess fileobj gets automatically
converted. In any case, using the fd is better.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

test/py/unittests.py

@@ -262,8 +262,8 @@ class SimpleCaptureMethods(CameraTesterBase):
         running = True
         while running:
             events = sel.select()
-            for key, mask in events:
-                os.read(key.fileobj, 8)
+            for key, _ in events:
+                os.read(key.fd, 8)
 
                 ready_reqs = cm.get_ready_requests()