crush: sync up with userspace

.. up to ceph.git commit 1db1abc8328d ("crush: eliminate ad hoc diff
between kernel and userspace").  This fixes a bunch of recently pulled
coding style issues and makes includes a bit cleaner.

A patch "crush:Make the function crush_ln static" from Nicholas Krause
<xerofoify@gmail.com> is folded in as crush_ln() has been made static
in userspace as well.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

include/linux/crush/hash.h

@@ -1,6 +1,12 @@
 #ifndef CEPH_CRUSH_HASH_H
 #define CEPH_CRUSH_HASH_H
 
+#ifdef __KERNEL__
+# include <linux/types.h>
+#else
+# include "crush_compat.h"
+#endif
+
 #define CRUSH_HASH_RJENKINS1   0
 
 #define CRUSH_HASH_DEFAULT CRUSH_HASH_RJENKINS1