fs: xattr_handler table should be const

The entries in xattr handler table should be immutable (ie const)
like other operation tables.

Later patches convert common filesystems. Uncoverted filesystems
will still work, but will generate a compiler warning.

Signed-off-by: Stephen Hemminger <shemminger@vyatta.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/include/linux/generic_acl.h b/include/linux/generic_acl.h
index ca666d1..574bea4 100644
--- a/include/linux/generic_acl.h
+++ b/include/linux/generic_acl.h
@@ -5,8 +5,8 @@
 
 struct inode;
 
-extern struct xattr_handler generic_acl_access_handler;
-extern struct xattr_handler generic_acl_default_handler;
+extern const struct xattr_handler generic_acl_access_handler;
+extern const struct xattr_handler generic_acl_default_handler;
 
 int generic_acl_init(struct inode *, struct inode *);
 int generic_acl_chmod(struct inode *);