NFSD: The patch fixes writing beyond the array.

If nfsd fails to find an exported via NFS file in the readahead cache,
it should increment corresponding nfsdstats counter (ra_depth[10]), but
due to a bug writes beside the stat array, corrupting following field.

In a kernel with NFSDv4 compiled in it corrupts (inc) NFS4 counter:
the number of individual nfsv4 operations.
In a kernel with NFSDv4 disabled it corrupts (inc) some other data,
that lays in the memory beyond nfsdstats.

Signed-off-by: Konstantin Khorenko <khorenko@openvz.org>

--- a/fs/nfsd/vfs.c.nfsd	2011-01-05 03:50:19.000000000 +0300
+++ b/fs/nfsd/vfs.c	2011-02-01 16:39:28.000000000 +0300
@@ -809,7 +809,7 @@ nfsd_get_raparms(dev_t dev, ino_t ino)
 		if (ra->p_count == 0)
 			frap = rap;
 	}
-	depth = nfsdstats.ra_size*11/10;
+	depth = nfsdstats.ra_size;
 	if (!frap) {	
 		spin_unlock(&rab->pb_lock);
 		return NULL;