NFSv4: Allow tracing of NFSv4 fsync calls

I appear to have missed this when adding the ftrace probes.

Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>
diff --git a/fs/nfs/nfs4file.c b/fs/nfs/nfs4file.c
index 8b46389..0de62f7 100644
--- a/fs/nfs/nfs4file.c
+++ b/fs/nfs/nfs4file.c
@@ -10,6 +10,8 @@
 #include "fscache.h"
 #include "pnfs.h"
 
+#include "nfstrace.h"
+
 #ifdef CONFIG_NFS_V4_2
 #include "nfs42.h"
 #endif
@@ -100,6 +102,8 @@
 	int ret;
 	struct inode *inode = file_inode(file);
 
+	trace_nfs_fsync_enter(inode);
+
 	do {
 		ret = filemap_write_and_wait_range(inode->i_mapping, start, end);
 		if (ret != 0)
@@ -118,6 +122,7 @@
 		end = LLONG_MAX;
 	} while (ret == -EAGAIN);
 
+	trace_nfs_fsync_exit(inode, ret);
 	return ret;
 }