Subject: spufs: fix another off-by-one bug in mbox_read

Signed-off-by: Arnd Bergmann <arnd.bergmann@de.ibm.com>

Index: linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
===================================================================
--- linux-2.6.orig/arch/powerpc/platforms/cell/spufs/file.c
+++ linux-2.6/arch/powerpc/platforms/cell/spufs/file.c
@@ -385,7 +385,7 @@ static ssize_t spufs_mbox_read(struct fi
 	udata = (void __user *)buf;
 
 	spu_acquire(ctx);
-	for (count = 0; count <= len; count += 4, udata++) {
+	for (count = 0; (count + 4) <= len; count += 4, udata++) {
 		int ret;
 		ret = ctx->ops->mbox_read(ctx, &mbox_data);
 		if (ret == 0)