vppinfra: make _vec_len() read-only

Use of _vec_len() to set vector length breaks address sanitizer.
Users should use vec_set_len(), vec_inc_len(), vec_dec_len () instead.

Type: improvement
Change-Id: I441ae948771eb21c23a61f3ff9163bdad74a2cb8
Signed-off-by: Damjan Marion <damarion@cisco.com>
diff --git a/src/vppinfra/serialize.c b/src/vppinfra/serialize.c
index 95eca96..d84d7ca 100644
--- a/src/vppinfra/serialize.c
+++ b/src/vppinfra/serialize.c
@@ -714,7 +714,7 @@
 	  n_left_b -= n;
 	  n_left_o -= n;
 	  if (n_left_o == 0)
-	    _vec_len (s->overflow_buffer) = 0;
+	    vec_set_len (s->overflow_buffer, 0);
 	  else
 	    vec_delete (s->overflow_buffer, n, 0);
 	}
@@ -771,7 +771,7 @@
   if (n_left_o == 0 && s->overflow_buffer)
     {
       s->current_overflow_index = 0;
-      _vec_len (s->overflow_buffer) = 0;
+      vec_set_len (s->overflow_buffer, 0);
     }
 
   n_left_to_read = n_bytes_to_read;
@@ -923,7 +923,7 @@
   serialize_close (m);		/* frees overflow buffer */
 
   if (s->buffer)
-    _vec_len (s->buffer) = s->current_buffer_index;
+    vec_set_len (s->buffer, s->current_buffer_index);
   result = s->buffer;
   clib_memset (m, 0, sizeof (m[0]));
   return result;
@@ -1161,7 +1161,7 @@
 	serialize_error (m, clib_error_return_unix (0, "write"));
     }
   if (n == s->current_buffer_index)
-    _vec_len (s->buffer) = 0;
+    vec_set_len (s->buffer, 0);
   else
     vec_delete (s->buffer, n, 0);
   s->current_buffer_index = vec_len (s->buffer);
@@ -1197,7 +1197,7 @@
   if (!is_read)
     {
       m->stream.n_buffer_bytes = vec_len (m->stream.buffer);
-      _vec_len (m->stream.buffer) = 0;
+      vec_set_len (m->stream.buffer, 0);
     }
 
   m->header.data_function = is_read ? clib_file_read : clib_file_write;