sctp: remove redundant check when walking through a list of TLV parameters

When  pos.v <= (void *)chunk + end - ntohs(pos.p->length) and
ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t) these two expressions are all true,
pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) *must* be true.

This patch removes this kind of redundant check.
It's same to  _sctp_walk_errors macro.
Signed-off-by: NShan Wei <shanwei@cn.fujitsu.com>
Signed-off-by: NVlad Yasevich <vladislav.yasevich@hp.com>
Signed-off-by: NWei Yongjun <yjwei@cn.fujitsu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>

include/net/sctp/sctp.h

@@ -531,7 +531,6 @@ _sctp_walk_params((pos), (chunk), ntohs((chunk)->chunk_hdr.length), member)
 
 #define _sctp_walk_params(pos, chunk, end, member)\
 for (pos.v = chunk->member;\
-     pos.v <= (void *)chunk + end - sizeof(sctp_paramhdr_t) &&\
      pos.v <= (void *)chunk + end - ntohs(pos.p->length) &&\
      ntohs(pos.p->length) >= sizeof(sctp_paramhdr_t);\
      pos.v += WORD_ROUND(ntohs(pos.p->length)))
@@ -542,7 +541,6 @@ _sctp_walk_errors((err), (chunk_hdr), ntohs((chunk_hdr)->length))
 #define _sctp_walk_errors(err, chunk_hdr, end)\
 for (err = (sctp_errhdr_t *)((void *)chunk_hdr + \
 	    sizeof(sctp_chunkhdr_t));\
-     (void *)err <= (void *)chunk_hdr + end - sizeof(sctp_errhdr_t) &&\
      (void *)err <= (void *)chunk_hdr + end - ntohs(err->length) &&\
      ntohs(err->length) >= sizeof(sctp_errhdr_t); \
      err = (sctp_errhdr_t *)((void *)err + WORD_ROUND(ntohs(err->length))))