NFS: fix compiler warnings on 64-bit platforms

Introduced by NFS aio+dio patches.

Test plan:
Compile kernel with CONFIG_NFS enabled on 64-bit hardware.

Signed-off-by: Chuck Lever <cel@netapp.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/direct.c b/fs/nfs/direct.c
index 1e3725e..b4bbf6d 100644
--- a/fs/nfs/direct.c
+++ b/fs/nfs/direct.c
@@ -365,7 +365,7 @@
 		rpc_execute(&data->task);
 		unlock_kernel();
 
-		dfprintk(VFS, "NFS: %4d initiated direct read call (req %s/%Ld, %u bytes @ offset %Lu)\n",
+		dfprintk(VFS, "NFS: %5u initiated direct read call (req %s/%Ld, %zu bytes @ offset %Lu)\n",
 				data->task.tk_pid,
 				inode->i_sb->s_id,
 				(long long)NFS_FILEID(inode),
@@ -686,7 +686,7 @@
 		rpc_execute(&data->task);
 		unlock_kernel();
 
-		dfprintk(VFS, "NFS: %4d initiated direct write call (req %s/%Ld, %u bytes @ offset %Lu)\n",
+		dfprintk(VFS, "NFS: %5u initiated direct write call (req %s/%Ld, %zu bytes @ offset %Lu)\n",
 				data->task.tk_pid,
 				inode->i_sb->s_id,
 				(long long)NFS_FILEID(inode),