IB/qib: Fix an incorrect log message

There is a cut-and-paste typo in the function qib_pci_slot_reset()
where it prints that the "link_reset" function is called rather than
the "slot_reset" function.  This makes the message misleading.

Signed-off-by: Betty Dall <betty.dall@hp.com>
Signed-off-by: Roland Dreier <roland@purestorage.com>