[SCTP]: Fix compiler warning about const qualifiers

Fix 3 warnings about discarding const qualifiers:

net/sctp/ulpevent.c:862: warning: passing argument 1 of 'sctp_event2skb' discards qualifiers from pointer target type
net/sctp/sm_statefuns.c:4393: warning: passing argument 1 of 'SCTP_ASOC' discards qualifiers from pointer target type
net/sctp/socket.c:5874: warning: passing argument 1 of 'cmsg_nxthdr' discards qualifiers from pointer target type

Signed-off-by: Vlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 2 deletions

diff --git a/net/sctp/socket.c b/net/sctp/socket.c
index d994d822900d..998e63a31311 100644
--- a/net/sctp/socket.c
+++ b/net/sctp/socket.c
@@ -5868,11 +5868,12 @@ SCTP_STATIC int sctp_msghdr_parse(const struct msghdr *msg,
                                   sctp_cmsgs_t *cmsgs)
 {
         struct cmsghdr *cmsg;
+        struct msghdr *my_msg = (struct msghdr *)msg;
 
         for (cmsg = CMSG_FIRSTHDR(msg);
              cmsg != NULL;
-             cmsg = CMSG_NXTHDR((struct msghdr*)msg, cmsg)) {
-                if (!CMSG_OK(msg, cmsg))
+             cmsg = CMSG_NXTHDR(my_msg, cmsg)) {
+                if (!CMSG_OK(my_msg, cmsg))
                         return -EINVAL;
 
                 /* Should we parse this header or ignore?  */