IB/qib: Fix uninitialized pointer if CONFIG_PCI_MSI not set

If CONFIG_PCI_MSI is not set, and a QLE7140 is present, the pointer
"dd" is uninitialized.

Signed-off-by: Ralph Campbell <ralph.campbell@qlogic.com>
Signed-off-by: Roland Dreier <rolandd@cisco.com>