vfs: export do_splice_direct() to modules

Export do_splice_direct() to modules.  Needed by overlay filesystem.

Signed-off-by: Miklos Szeredi <mszeredi@suse.cz>
(cherry picked from commit 1c118596a7682912106c80007102ce0184c77780)
Signed-off-by: Alex Shi <alex.shi@linaro.org>
diff --git a/fs/splice.c b/fs/splice.c
index 12028fa..ffb92b9 100644
--- a/fs/splice.c
+++ b/fs/splice.c
@@ -1327,6 +1327,7 @@
 
 	return ret;
 }
+EXPORT_SYMBOL(do_splice_direct);
 
 static int splice_pipe_to_pipe(struct pipe_inode_info *ipipe,
 			       struct pipe_inode_info *opipe,