IrDA: Incorrect TTP header reservation

We must reserve SAR + MAX_HEADER bytes for IrLMP to fit in.
This fixes an oops reported (and fixed) by Jeet Chaudhuri, when max_sdu_size
is greater than 0.
Signed-off-by: Samuel Ortiz <samuel@sortiz.org>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Adrian Bunk <bunk@stusta.de>

net/irda/irttp.c

@@ -1100,7 +1100,7 @@ int irttp_connect_request(struct tsap_cb *self, __u8 dtsap_sel,
 			return -ENOMEM;
 
 		/* Reserve space for MUX_CONTROL and LAP header */
-		skb_reserve(tx_skb, TTP_MAX_HEADER);
+		skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
 	} else {
 		tx_skb = userdata;
 		/*
@@ -1348,7 +1348,7 @@ int irttp_connect_response(struct tsap_cb *self, __u32 max_sdu_size,
 			return -ENOMEM;
 
 		/* Reserve space for MUX_CONTROL and LAP header */
-		skb_reserve(tx_skb, TTP_MAX_HEADER);
+		skb_reserve(tx_skb, TTP_MAX_HEADER + TTP_SAR_HEADER);
 	} else {
 		tx_skb = userdata;
 		/*