SUNRPC: remove BUG_ON in svc_xprt_received

Replace BUG_ON() with a WARN_ON_ONCE() and early return.

Signed-off-by: Weston Andros Adamson <dros@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/net/sunrpc/svc_xprt.c b/net/sunrpc/svc_xprt.c
index 194d865..be89bb6 100644
--- a/net/sunrpc/svc_xprt.c
+++ b/net/sunrpc/svc_xprt.c
@@ -218,7 +218,9 @@
  */
 static void svc_xprt_received(struct svc_xprt *xprt)
 {
-	BUG_ON(!test_bit(XPT_BUSY, &xprt->xpt_flags));
+	WARN_ON_ONCE(!test_bit(XPT_BUSY, &xprt->xpt_flags));
+	if (!test_bit(XPT_BUSY, &xprt->xpt_flags))
+		return;
 	/* As soon as we clear busy, the xprt could be closed and
 	 * 'put', so we need a reference to call svc_xprt_enqueue with:
 	 */