PCI: aardvark: Deduplicate code in advk_pcie_rd_conf()

PCI: aardvark: Deduplicate code in advk_pcie_rd_conf()

commit 476908e593e65c18c1a513f111ec0750861d373d upstream.

Avoid code repetition in advk_pcie_rd_conf() by handling errors with
goto jump, as is customary in kernel.

Link: https://lore.kernel.org/r/20211005180952.6812-9-kabel@kernel.org
Fixes: 810b0dd978b0 ("PCI: aardvark: Fix reporting CRS value")
Signed-off-by: Marek Behún <kabel@kernel.org>
Signed-off-by: Lorenzo Pieralisi <lorenzo.pieralisi@arm.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>