skd: Fix incomplete cleanup of MSI-X interrupt

When enabling MSI-X interrupts fails due to lack of memory
the call to pci_disable_msix() is missed and the device is
left with MSI-X interrupts enabled while the driver assumes
otherwise. This update fixes the described misbehaviour and
cleans up the code of skd_release_msix() function.

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>
Cc: Kyungmin Park <kyungmin.park@samsung.com>
Cc: linux-pci@vger.kernel.org
Signed-off-by: Jens Axboe <axboe@fb.com>