media: imx8mq-mipi-csi2: Use %pe format specifier

media: imx8mq-mipi-csi2: Use %pe format specifier

The %pe format specifier is designed to print error pointers. It prints
a symbolic error name (eg. -EINVAL) and it makes the code simpler by
omitting PTR_ERR().

This patch fixes this cocci report:
./platform/nxp/imx8mq-mipi-csi2.c:422:23-30: WARNING: Consider using %pe to print PTR_ERR()

Signed-off-by: Ricardo Ribalda <ribalda@chromium.org>
Reviewed-by: Martin Kepplinger-Novakovic <martink@posteo.de>
Acked-by: Sakari Ailus <sakari.ailus@linux.intel.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>