sctp: fix SSN comparision

This function actually operates on u32 yet its paramteres were declared
as u16, causing integer truncation upon calling.

Note in patch context that ADDIP_SERIAL_SIGN_BIT is already 32 bits.
Signed-off-by: Marcelo Ricardo Leitner <marcelo.leitner@gmail.com>
Acked-by: Neil Horman <nhorman@tuxdriver.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

include/net/sctp/sm.h

@@ -382,7 +382,7 @@ enum {
 	ADDIP_SERIAL_SIGN_BIT = (1<<31)
 };
 
-static inline int ADDIP_SERIAL_gte(__u16 s, __u16 t)
+static inline int ADDIP_SERIAL_gte(__u32 s, __u32 t)
 {
 	return ((s) == (t)) || (((t) - (s)) & ADDIP_SERIAL_SIGN_BIT);
 }