bus: imx-weim: fix NULL but dereferenced coccicheck error

Fix following coccicheck warning:
./drivers/bus/imx-weim.c:355:18-21: ERROR: pdev is NULL but dereferenced.

Signed-off-by: Wan Jiabing <wanjiabing@vivo.com>
Acked-by: Ivan Bornyakov <i.bornyakov@metrotek.ru>
Signed-off-by: Shawn Guo <shawnguo@kernel.org>