pci: Save MSIX ctrl value before pci_mask_msix call

[kgalazka]

Summary

Function pci_mask_msix uses cached value of MSI-X CTRL
register to verify if vector index is valid. Update
that value in pci_alloc_msix_method before it is
used to avoid kernel panic.

Signed-off-by: Krzysztof Galazka <[e-mail]>

[jhb]

sys/dev/pci/pci.c

1930

Huh. I would maybe keep the code unchanged below and just do an extra assignment here? The normal style is a blank line before comments, but this is also part of the logical masking operation so maybe:

/*
  * Mask all vectors.  Note that the message index assertion in
  * pci_mask_msix requires msix_ctrl to be set.
  */
cfg->msix.msix_ctrl = ctrl;
for (i = 0; i < msgnum; i++)

[kgalazka]

Implement feedback from jhb.

[kgalazka]

@jhb Is there anything else you'd like me to change in this patch?