net: systemport: don't use bitmap_weight() in bcm_sysport_rule_set()

Don't call bitmap_weight() if the following code can get by
without it.
Signed-off-by: Yury Norov <yury.norov@gmail.com>
Acked-by: Florian Fainelli <f.fainelli@gmail.com>

drivers/net/ethernet/broadcom/bcmsysport.c

@@ -2180,13 +2180,9 @@ static int bcm_sysport_rule_set(struct bcm_sysport_priv *priv,
 	if (nfc->fs.ring_cookie != RX_CLS_FLOW_WAKE)
 		return -EOPNOTSUPP;
 
-	/* All filters are already in use, we cannot match more rules */
-	if (bitmap_weight(priv->filters, RXCHK_BRCM_TAG_MAX) ==
-	    RXCHK_BRCM_TAG_MAX)
-		return -ENOSPC;
-
 	index = find_first_zero_bit(priv->filters, RXCHK_BRCM_TAG_MAX);
 	if (index >= RXCHK_BRCM_TAG_MAX)
+		/* All filters are already in use, we cannot match more rules */
 		return -ENOSPC;
 
 	/* Location is the classification ID, and index is the position