media: vsp1: Fix BRx conditional path in WPF

When a BRx is provided by a pipeline, the WPF must determine the master
layer. Currently the condition to check this identifies pipe->bru ||
pipe->num_inputs > 1.

The code then moves on to dereference pipe->bru, thus the check fails
static analysers on the possibility that pipe->num_inputs could be
greater than 1 without pipe->bru being set.

The reality is that the pipeline must have a BRx to support more than
one input, thus this could never cause a fault - however it also
identifies that the num_inputs > 1 check is redundant.

Remove the redundant check - and always configure the master layer
appropriately when we have a BRx configured in our pipeline.

Fixes: 6134148f ("v4l: vsp1: Add support for the BRS entity")

Cc: stable@vger.kernel.org
Suggested-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>
Signed-off-by: Kieran Bingham <kieran.bingham+renesas@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>