Spare the function call in vdp_bytes().

But we might go back to it when we add the VFP, since much of the
code for I/O with the child process should be reuasable.

src/vdfp_pipe.c

@@ -298,15 +298,19 @@ check_pid(struct vdp_state *state, struct vsl_log *vsl, int options)
 	return (-1);
 }
 
-/* Assumes CHECK_OBJ* for req and state called by caller. */
-static int
-rw_child(struct req *req, struct vdp_state *state, enum vdp_action act,
-	 const void *ptr, ssize_t len)
+static int v_matchproto_(vdp_bytes_f)
+vdp_bytes(struct req *req, enum vdp_action act, void **priv, const void *ptr,
+	  ssize_t len)
 {
+	struct vdp_state *state;
 	struct pollfd *fds;
 	int retval;
 	ssize_t nbytes;
 
+	CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
+	assert(len >= 0);
+	AN(priv);
+	CAST_OBJ_NOTNULL(state, *priv, PIPE_VDP_STATE_MAGIC);
 	CHECK_OBJ_NOTNULL(state->obj, PIPE_VDP_MAGIC);
 	AN(state->obj->name);
 	AN(state->obj->path);
@@ -427,20 +431,6 @@ rw_child(struct req *req, struct vdp_state *state, enum vdp_action act,
 	return (0);
 }
 
-static int v_matchproto_(vdp_bytes_f)
-vdp_bytes(struct req *req, enum vdp_action act, void **priv, const void *ptr,
-	  ssize_t len)
-{
-	struct vdp_state *state;
-
-	CHECK_OBJ_NOTNULL(req, REQ_MAGIC);
-	assert(len >= 0);
-	AN(priv);
-	CAST_OBJ_NOTNULL(state, *priv, PIPE_VDP_STATE_MAGIC);
-
-	return (rw_child(req, state, act, ptr, len));
-}
-
 static int v_matchproto_(vdp_fini_f)
 vdp_fini(struct req *req, void **priv)
 {