- initialize header size correctly

This commit was SVN r977.

src/mca/ptl/tcp/src/ptl_tcp_sendfrag.c

@@ -131,7 +131,7 @@ int mca_ptl_tcp_send_frag_init(
     sendfrag->frag_vec_ptr = sendfrag->frag_vec;
     sendfrag->frag_vec_cnt = (size == 0) ? 1 : 2;
     sendfrag->frag_vec[0].iov_base = (lam_iov_base_ptr_t)hdr;
-    sendfrag->frag_vec[0].iov_len = sizeof(mca_ptl_base_header_t);
+    sendfrag->frag_vec[0].iov_len = hdr->hdr_common.hdr_size;
     return LAM_SUCCESS;
 }