media: adv7842: Use %pe format specifier

media: adv7842: 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:
./i2c/adv7842.c:3470:16-23: WARNING: Consider using %pe to print PTR_ERR()

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