media: mceusb: Avoid GFP_ATOMIC where it is not needed

There is no point in using GFP_ATOMIC here.
It is a probe function, and GFP_KERNEL is already used the line before
and the line after.

Use GFP_KERNEL instead.

Signed-off-by: Christophe JAILLET <christophe.jaillet@wanadoo.fr>
Signed-off-by: Sean Young <sean@mess.org>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>