[GFS2] Macros removal in gfs2.h

As suggested by Pekka Enberg <penberg@cs.helsinki.fi>.

The DIV_RU macro is renamed DIV_ROUND_UP and and moved to kernel.h
The other macros are gone from gfs2.h as (although not requested
by Pekka Enberg) are a number of included header file which are now
included individually. The inode number comparison function is
now an inline function.

The DT2IF and IF2DT may be addressed in a future patch.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/main.c

@@ -14,11 +14,15 @@
 #include <linux/buffer_head.h>
 #include <linux/module.h>
 #include <linux/init.h>
+#include <linux/gfs2_ondisk.h>
 #include <asm/semaphore.h>
 
 #include "gfs2.h"
+#include "lm_interface.h"
+#include "incore.h"
 #include "ops_fstype.h"
 #include "sys.h"
+#include "util.h"
 
 /**
  * init_gfs2_fs - Register GFS2 as a filesystem