media: nxp: imx8-isi: Drop unneeded v4l2_m2m_get_vq() NULL check

media: nxp: imx8-isi: Drop unneeded v4l2_m2m_get_vq() NULL check

The v4l2_m2m_get_vq() function never returns NULL. The check may have
been intended to catch invalid format types, but that's not needed as
the V4L2 core picks the appropriate VIDIOC_S_FMT ioctl handler based on
the format type, so the type can't be incorrect. Drop the unneeded
return value check.

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Reviewed-by: Frank Li <Frank.Li@nxp.com>
Signed-off-by: Hans Verkuil <hverkuil+cisco@kernel.org>