NTB: Fix zero size or integer overflow in ntb_set_mw

A plain 32 bit integer will overflow for values over 4GiB.

Change the plain integer size to the appropriate size type in
ntb_set_mw.  Change the type of the size parameter and two local
variables used for size.

Even if there is no overflow, a size of zero is invalid here.

Reported-by: Juyoung Jung <jjung@micron.com>
Signed-off-by: Allen Hubbe <Allen.Hubbe@emc.com>
Signed-off-by: Jon Mason <jdmason@kudzu.us>

drivers/ntb/ntb_transport.c

@@ -629,13 +629,16 @@ static void ntb_free_mw(struct ntb_transport_ctx *nt, int num_mw)
 }
 
 static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
-		      unsigned int size)
+		      resource_size_t size)
 {
 	struct ntb_transport_mw *mw = &nt->mw_vec[num_mw];
 	struct pci_dev *pdev = nt->ndev->pdev;
-	unsigned int xlat_size, buff_size;
+	size_t xlat_size, buff_size;
 	int rc;
 
+	if (!size)
+		return -EINVAL;
+
 	xlat_size = round_up(size, mw->xlat_align_size);
 	buff_size = round_up(size, mw->xlat_align);
 
@@ -655,7 +658,7 @@ static int ntb_set_mw(struct ntb_transport_ctx *nt, int num_mw,
 	if (!mw->virt_addr) {
 		mw->xlat_size = 0;
 		mw->buff_size = 0;
-		dev_err(&pdev->dev, "Unable to alloc MW buff of size %d\n",
+		dev_err(&pdev->dev, "Unable to alloc MW buff of size %zu\n",
 			buff_size);
 		return -ENOMEM;
 	}