staging/rdma/hfi1: Unexpected link up pkey values are not an error

Only warn when link up pkeys are not what we expect.  Also, allow
for the pkey to already be initialized.

Reviewed-by: Arthur Kepner <arthur.kepner@intel.com>
Signed-off-by: Dean Luick <dean.luick@intel.com>
Signed-off-by: Jubin John <jubin.john@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>