csiostor: Remove superfluous call to pci_disable_msix()

There is no need to call pci_disable_msix() in case
the previous call to pci_enable_msix() failed

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Reviewed-by: Tomas Henzl <thenzl@redhat.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>