msi & gcc build problem

[Patrick Welche <prlw1%cam.ac.uk@localhost>]

sys/arch/x86/pci/msipci.c has:

    KASSERT(pci_get_capability(pc, tag, PCI_CAP_MSI, &off, NULL) != 0);
...
    ctl = pci_conf_read(pc, tag, off + PCI_MSI_CTL);

but gcc can't work out that the off was set in the first function call:

--- msipic.o ---
../../../../arch/x86/pci/msipic.c: In function 'msi_addroute':
../../../../arch/x86/pci/msipic.c:392:6: error: 'off' is used uninitialized in t
his function [-Werror=uninitialized]
  ctl = pci_conf_read(pc, tag, off + PCI_MSI_CTL);


I have been building with NOGCCERROR=yes in mk.conf - thoughts on a more
elegant solution to quell the warning?

Cheers,

Patrick