Per the recent discussions at the Linux Plumbers Conference, when
enabling MSI or MSI-X, generate a test interrupt to verify the
interrupt routing is working properly.  If the test interrupt fails,
fall back to MSI first, and if that fails as well, to INTx.  If the
interrupt test fails with INTx, log an error and fail the PCI probe.

Also changed the use of spin_(lock|unlock) to the _irq(save|restore)
variants in the interrupt handlers because with multi-message MSI-X,
both interrupt handlers can now run in parallel.
Signed-off-by: NJames Smart <James.Smart@emulex.com>
Signed-off-by: NJames Bottomley <James.Bottomley@HansenPartnership.com>