net: Suppress the "Comparison to NULL could be written" warnings

This is to suppress the checkpatch.pl warning "Comparison to NULL
could be written". No functional changes here.

Signed-off-by: Jia He <hejianet@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
diff --git a/net/sctp/proc.c b/net/sctp/proc.c
index 09e16c2..206377f 100644
--- a/net/sctp/proc.c
+++ b/net/sctp/proc.c
@@ -81,7 +81,7 @@
 
 	snmp_get_cpu_field_batch(buff, sctp_snmp_list,
 				 net->sctp.sctp_statistics);
-	for (i = 0; sctp_snmp_list[i].name != NULL; i++)
+	for (i = 0; sctp_snmp_list[i].name; i++)
 		seq_printf(seq, "%-32s\t%ld\n", sctp_snmp_list[i].name,
 						buff[i]);