remove nfs_init declaration

git-svn-id: https://rt-thread.googlecode.com/svn/trunk@2246 bbd45198-f89e-11dd-88c7-29a3b14d5316

components/init/components_init.c

@@ -79,7 +79,6 @@ void rt_components_init(void)
 #endif
 
 #if defined(RT_USING_DFS_NFS) && defined(RT_USING_LWIP)
-	extern int nfs_init(void);
 	/* initialize NFSv3 client file system */
 	nfs_init();
 #endif