vfio/pci: fix a couple of spelling mistakes

There are several spelling mistakes, as follows:
thru ==> through
presense ==> presence
Signed-off-by: Zhen Lei <thunder.leizhen@huawei.com>
Reviewed-by: Eric Auger <eric.auger@redhat.com>
Message-Id: <20210326083528.1329-4-thunder.leizhen@huawei.com>
Signed-off-by: Alex Williamson <alex.williamson@redhat.com>

drivers/vfio/pci/vfio_pci_config.c

@@ -101,7 +101,7 @@ static const u16 pci_ext_cap_length[PCI_EXT_CAP_ID_MAX + 1] = {
 /*
  * Read/Write Permission Bits - one bit for each bit in capability
  * Any field can be read if it exists, but what is read depends on
- * whether the field is 'virtualized', or just pass thru to the
+ * whether the field is 'virtualized', or just pass through to the
  * hardware.  Any virtualized field is also virtualized for writes.
  * Writes are only permitted if they have a 1 bit here.
  */

drivers/vfio/pci/vfio_pci_nvlink2.c

@@ -219,7 +219,7 @@ int vfio_pci_nvdia_v100_nvlink2_init(struct vfio_pci_device *vdev)
 	unsigned long events = VFIO_GROUP_NOTIFY_SET_KVM;
 
 	/*
-	 * PCI config space does not tell us about NVLink presense but
+	 * PCI config space does not tell us about NVLink presence but
 	 * platform does, use this.
 	 */
 	npu_dev = pnv_pci_get_npu_dev(vdev->pdev, 0);
@@ -402,7 +402,7 @@ int vfio_pci_ibm_npu2_init(struct vfio_pci_device *vdev)
 	u32 link_speed = 0xff;
 
 	/*
-	 * PCI config space does not tell us about NVLink presense but
+	 * PCI config space does not tell us about NVLink presence but
 	 * platform does, use this.
 	 */
 	if (!pnv_pci_get_gpu_dev(vdev->pdev))