caif: Bugfix - Increase default headroom size for control channel.

Headroom size for control channel must be at least 48 bytes in some scenarios.
Signed-off-by: Sjur Braendeland <sjur.brandeland@stericsson.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

net/caif/cfpkt_skbuff.c

@@ -9,7 +9,7 @@
 #include <linux/hardirq.h>
 #include <net/caif/cfpkt.h>
 
-#define PKT_PREFIX  16
+#define PKT_PREFIX  48
 #define PKT_POSTFIX 2
 #define PKT_LEN_WHEN_EXTENDING 128
 #define PKT_ERROR(pkt, errmsg) do {	   \