constify dentry_operations: rest

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>

fs/pipe.c

@@ -870,7 +870,7 @@ static char *pipefs_dname(struct dentry *dentry, char *buffer, int buflen)
 				dentry->d_inode->i_ino);
 }
 
-static struct dentry_operations pipefs_dentry_operations = {
+static const struct dentry_operations pipefs_dentry_operations = {
 	.d_delete	= pipefs_delete_dentry,
 	.d_dname	= pipefs_dname,
 };