[media] DaVinci-VPBE: Check return value of a setup_if_config() call in vpbe_set_output()

* A function was called over the pointer "setup_if_config" in the data
  structure "venc_platform_data". But the return value was not used so far.
  Thus assign it to the local variable "ret" which will be checked with
  the next statement.

  Fixes: 9a7f95ad ("[media] davinci vpbe: add dm365 VPBE display driver changes")

* Pass a value to this function call without storing it in an intermediate
  variable before.

* Delete the local variable "if_params" which became unnecessary with
  this refactoring.

Acked-by: Lad, Prabhakar <prabhakar.csengg@gmail.com>
Signed-off-by: Markus Elfring <elfring@users.sourceforge.net>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@s-opensource.com>