powerpc/powernv: Use CPU-endian hub diag-data type in pnv_eeh_get_and_dump_hub_diag()

The hub diag-data type is filled with big-endian data by OPAL call
opal_pci_get_hub_diag_data(). We need convert it to CPU-endian value
before using it. The issue is reported by sparse as pointed by Michael
Ellerman:

  eeh-powernv.c:1309:21: warning: restricted __be16 degrades to integer

This converts hub diag-data type to CPU-endian before using it in
pnv_eeh_get_and_dump_hub_diag().

Fixes: 2a485ad7c8 ("powerpc/powernv: Drop PHB operation next_error()")
Cc: stable@vger.kernel.org # v4.1+
Suggested-by: Michael Ellerman <mpe@ellerman.id.au>
Signed-off-by: Gavin Shan <gwshan@linux.vnet.ibm.com>
Reviewed-by: Russell Currey <ruscur@russell.cc>
Signed-off-by: Michael Ellerman <mpe@ellerman.id.au>

arch/powerpc/platforms/powernv/eeh-powernv.c

@@ -1314,7 +1314,7 @@ static void pnv_eeh_get_and_dump_hub_diag(struct pci_controller *hose)
 		return;
 	}
 
-	switch (data->type) {
+	switch (be16_to_cpu(data->type)) {
 	case OPAL_P7IOC_DIAG_TYPE_RGC:
 		pr_info("P7IOC diag-data for RGC\n\n");
 		pnv_eeh_dump_hub_diag_common(data);