drm/v3d: Fix missing error code in v3d_submit_cpu_ioctl()

Smatch warns:
	drivers/gpu/drm/v3d/v3d_submit.c:1222 v3d_submit_cpu_ioctl()
	warn: missing error code 'ret'

When there is no job type or job is submitted with wrong number of BOs
it is an error path, ret is zero at this point which is incorrect
return.

Fix this by changing it to -EINVAL.

Fixes: aafc1a2b ("drm/v3d: Add a CPU job submission")
Signed-off-by: Harshit Mogalapalli <harshit.m.mogalapalli@oracle.com>
Reviewed-by: Melissa Wen <mwen@igalia.com>
Signed-off-by: Melissa Wen <melissa.srw@gmail.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20231204122102.181298-1-harshit.m.mogalapalli@oracle.com