bnxt_en: Fix the 'Invalid VF' id check in bnxt_vf_ndo_prep routine.

In bnxt_vf_ndo_prep (which is called by bnxt_get_vf_config ndo), there is a
check for "Invalid VF id". Currently, the check is done against max_vfs.
However, the user doesn't always create max_vfs. So, the check should be
against the created number of VFs. The number of bnxt_vf_info structures
that are allocated in bnxt_alloc_vf_resources routine is the "number of
requested VFs". So, if an "invalid VF id" falls between the requested
number of VFs and the max_vfs, the driver will be dereferencing an invalid
pointer.

Fixes: c0c050c58d ("bnxt_en: New Broadcom ethernet driver.")
Signed-off-by: Venkat Devvuru <venkatkumar.duvvuru@broadcom.com>
Signed-off-by: Michael Chan <michael.chan@broadcom.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

drivers/net/ethernet/broadcom/bnxt/bnxt_sriov.c

@@ -70,7 +70,7 @@ static int bnxt_vf_ndo_prep(struct bnxt *bp, int vf_id)
 		netdev_err(bp->dev, "vf ndo called though sriov is disabled\n");
 		return -EINVAL;
 	}
-	if (vf_id >= bp->pf.max_vfs) {
+	if (vf_id >= bp->pf.active_vfs) {
 		netdev_err(bp->dev, "Invalid VF id %d\n", vf_id);
 		return -EINVAL;
 	}