media: rcar-vin: fix redeclaration of symbol

When adding support for parallel subdev for Gen3 it was missed that the
symbol 'i' in rvin_group_link_notify() was already declared, remove the
dupe as it's only used as a loop variable this have no functional
change. This fixes warning:

    rcar-core.c:117:52: originally declared here
    rcar-core.c:173:30: warning: symbol 'i' shadows an earlier one

Fixes: 1284605d ("media: rcar-vin: Handle parallel subdev in link_notify")

Signed-off-by: Niklas Söderlund <niklas.soderlund+renesas@ragnatech.se>
Acked-by: Jacopo Mondi <jacopo+renesas@jmondi.org>
Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@kernel.org>