dcbnl : Fix misleading dcb_app->priority explanation

Current explanation of dcb_app->priority is wrong. It says priority is
expected to be a 3-bit unsigned integer which is only true when working with
DCBx-IEEE. Use of dcb_app->priority by DCBx-CEE expects it to be 802.1p user
priority bitmap. Updated accordingly

This affects the cxgb4 driver, but I will post those changes as part of a
larger changeset shortly.

Fixes: 3e29027af4372 ("dcbnl: add support for ieee8021Qaz attributes")
Signed-off-by: Anish Bhatt <anish@chelsio.com>
Acked-by: John Fastabend <john.r.fastabend@intel.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/uapi/linux/dcbnl.h

@@ -148,7 +148,8 @@ struct cee_pfc {
  *
  * @selector: protocol identifier type
  * @protocol: protocol of type indicated
- * @priority: 3-bit unsigned integer indicating priority
+ * @priority: 3-bit unsigned integer indicating priority for IEEE
+ *            8-bit 802.1p user priority bitmap for CEE
  *
  * ----
  *  Selector field values

net/dcb/dcbnl.c

@@ -1776,7 +1776,7 @@ EXPORT_SYMBOL(dcb_getapp);
  *
  * Priority 0 is an invalid priority in CEE spec. This routine
  * removes applications from the app list if the priority is
- * set to zero.
+ * set to zero. Priority is expected to be 8-bit 802.1p user priority bitmap
  */
 int dcb_setapp(struct net_device *dev, struct dcb_app *new)
 {
@@ -1837,7 +1837,8 @@ EXPORT_SYMBOL(dcb_ieee_getapp_mask);
  *
  * This adds Application data to the list. Multiple application
  * entries may exists for the same selector and protocol as long
- * as the priorities are different.
+ * as the priorities are different. Priority is expected to be a
+ * 3-bit unsigned integer
  */
 int dcb_ieee_setapp(struct net_device *dev, struct dcb_app *new)
 {