bfa: Do not call pci_enable_msix() after it failed once

Function pci_enable_msix() should not be called in case
it threw a negative errno from a previous call.

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Acked-by: Anil Gurumurthy <anil.gurumurthy@qlogic.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>