media: atomisp: Fix __func__ style warnings

This patch fixes the checkpatch.pl warning:

Prefer using '"%s...", __func__' to using '<function name>',
this function's name, in a string

Signed-off-by: Baidyanath Kundu <kundubaidya99@gmail.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+huawei@kernel.org>