[media] media: venus: hfi_msgs: fix set but not used variables

This fixes a warning found when building with gcc7:

drivers/media/platform/qcom/venus/hfi_msgs.c:465:40:
warning: variable 'domain' set but not used [-Wunused-but-set-variable]
  u32 rem_bytes, num_props, codecs = 0, domain = 0;
                                        ^~~~~~
drivers/media/platform/qcom/venus/hfi_msgs.c:465:28:
warning: variable 'codecs' set but not used [-Wunused-but-set-variable]
  u32 rem_bytes, num_props, codecs = 0, domain = 0;

The warning is avoided by deleting the variables declaration.

Signed-off-by: Stanimir Varbanov <stanimir.varbanov@linaro.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>