staging/rdma/hfi1: Fix for module parameter hdrq_entsize when it's 0

If driver is loaded with parameter hdrq_entsize=0, then
there's a NULL dereference when the driver gets unloaded.
This causes a kernel Oops and prevents the module  from
being unloaded. This patch fixes this issue by making sure
-EINVAL gets returned when hdrq_entsize=0.

Reviewed-by: Chegondi, Harish <harish.chegondi@intel.com>
Reviewed-by: Haralanov, Mitko <mitko.haralanov@intel.com>
Signed-off-by: Sebastian Sanchez <sebastian.sanchez@intel.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/staging/rdma/hfi1/init.c

@@ -1351,6 +1351,7 @@ static int init_one(struct pci_dev *pdev, const struct pci_device_id *ent)
 	if (!encode_rcv_header_entry_size(hfi1_hdrq_entsize)) {
 		hfi1_early_err(&pdev->dev, "Invalid HdrQ Entry size %u\n",
 			       hfi1_hdrq_entsize);
+		ret = -EINVAL;
 		goto bail;
 	}