soc: amlogic: canvas: fix device leak on lookup

Make sure to drop the reference taken to the canvas platform device when
looking up its driver data.

Note that holding a reference to a device does not prevent its driver
data from going away so there is no point in keeping the reference.

Also note that commit 28f851e6afa8 ("soc: amlogic: canvas: add missing
put_device() call in meson_canvas_get()") fixed the leak in a lookup
error path, but the reference is still leaking on success.

Fixes: d4983983d987 ("soc: amlogic: add meson-canvas driver")
Cc: [e-mail] # 4.20: 28f851e6afa8
Cc: Yu Kuai <[e-mail]>
Signed-off-by: Johan Hovold <[e-mail]>
Reviewed-by: Martin Blumenstingl <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Neil Armstrong <[e-mail]>

drivers/soc/amlogic/meson-canvas.c

···
 	 * current state, this driver probe cannot return -EPROBE_DEFER
 	 */
 	canvas = dev_get_drvdata(&canvas_pdev->dev);
-	if (!canvas) {
-		put_device(&canvas_pdev->dev);
+	put_device(&canvas_pdev->dev);
+	if (!canvas)
 		return ERR_PTR(-EINVAL);
-	}
 
 	return canvas;
 }