const: constify remaining pipe_buf_operations

Signed-off-by: Alexey Dobriyan <adobriyan@gmail.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index bfa3e78..93c4e06 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -93,7 +93,7 @@
 
 
 /* Pipe buffer operations for a socket. */
-static struct pipe_buf_operations sock_pipe_buf_ops = {
+static const struct pipe_buf_operations sock_pipe_buf_ops = {
 	.can_merge = 0,
 	.map = generic_pipe_buf_map,
 	.unmap = generic_pipe_buf_unmap,