ofpbuf: Rename ofpbuf "private" member for C++ header compatibility.

From partner.

lib/ofpbuf.c

@@ -36,7 +36,7 @@ ofpbuf_use(struct ofpbuf *b, void *base, size_t allocated)
     b->size = 0;
     b->l2 = b->l3 = b->l4 = b->l7 = NULL;
     b->next = NULL;
-    b->private = NULL;
+    b->private_p = NULL;
 }
 
 /* Initializes 'b' as an empty ofpbuf with an initial capacity of 'size'

lib/ofpbuf.h

@@ -19,6 +19,10 @@
 
 #include <stddef.h>
 
+#ifdef  __cplusplus
+extern "C" {
+#endif
+
 /* Buffer for holding arbitrary data.  An ofpbuf is automatically reallocated
  * as necessary if it grows too large for the available memory. */
 struct ofpbuf {
@@ -34,7 +38,7 @@ struct ofpbuf {
     void *l7;                   /* Application data. */
 
     struct ofpbuf *next;        /* Next in a list of ofpbufs. */
-    void *private;              /* Private pointer for use by owner. */
+    void *private_p;            /* Private pointer for use by owner. */
 };
 
 void ofpbuf_use(struct ofpbuf *, void *, size_t);
@@ -70,4 +74,8 @@ void ofpbuf_clear(struct ofpbuf *);
 void *ofpbuf_pull(struct ofpbuf *, size_t);
 void *ofpbuf_try_pull(struct ofpbuf *, size_t);
 
+#ifdef  __cplusplus
+}
+#endif
+
 #endif /* ofpbuf.h */

lib/rconn.c

@@ -547,7 +547,7 @@ rconn_send(struct rconn *rc, struct ofpbuf *b,
     if (rconn_is_connected(rc)) {
         COVERAGE_INC(rconn_queued);
         copy_to_monitor(rc, b);
-        b->private = counter;
+        b->private_p = counter;
         if (counter) {
             rconn_packet_counter_inc(counter);
         }
@@ -845,7 +845,7 @@ try_send(struct rconn *rc)
 {
     int retval = 0;
     struct ofpbuf *next = rc->txq.head->next;
-    struct rconn_packet_counter *counter = rc->txq.head->private;
+    struct rconn_packet_counter *counter = rc->txq.head->private_p;
     retval = vconn_send(rc->vconn, rc->txq.head);
     if (retval) {
         if (retval != EAGAIN) {
@@ -914,7 +914,7 @@ flush_queue(struct rconn *rc)
     }
     while (rc->txq.n > 0) {
         struct ofpbuf *b = queue_pop_head(&rc->txq);
-        struct rconn_packet_counter *counter = b->private;
+        struct rconn_packet_counter *counter = b->private_p;
         if (counter) {
             rconn_packet_counter_dec(counter);
         }