PCI: rcar-host: Remove unused LIST_HEAD(res)

PCI: rcar-host: Remove unused LIST_HEAD(res)

Remove the unused LIST_HEAD(res) declaration from rcar_pcie_hw_enable().

The macro instantiation defines an unused 'struct list_head res' variable,
which conflicts with a valid resource loop-local 'struct resource *res'
declaration further down in the function, triggering a compiler variable
shadowing warning:

 drivers/pci/controller/pcie-rcar-host.c:357:34: warning: declaration of 'res' shadows a previous local [-Wshadow]
 357 |                  struct resource *res = win->res;

Fixes: ce351636c67f75a9 ("PCI: rcar: Add suspend/resume")
Signed-off-by: Lad Prabhakar <prabhakar.mahadev-lad.rj@bp.renesas.com>
Signed-off-by: Manivannan Sadhasivam <mani@kernel.org>
Reviewed-by: Geert Uytterhoeven <geert+renesas@glider.be>
Reviewed-by: Marek Vasut <marek.vasut+renesas@mailbox.org>
Link: https://patch.msgid.link/20260521091256.15737-1-prabhakar.mahadev-lad.rj@bp.renesas.com