memblock: Kill memblock_init()

memblock_init() initializes arrays for regions and memblock itself;
however, all these can be done with struct initializers and
memblock_init() can be removed.  This patch kills memblock_init() and
initializes memblock with struct initializer.

The only difference is that the first dummy entries don't have .nid
set to MAX_NUMNODES initially.  This doesn't cause any behavior
difference.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Yinghai Lu <yinghai@kernel.org>
Cc: Russell King <linux@arm.linux.org.uk>
Cc: Michal Simek <monstr@monstr.eu>
Cc: Paul Mundt <lethal@linux-sh.org>
Cc: "David S. Miller" <davem@davemloft.net>
Cc: Guan Xuetao <gxt@mprc.pku.edu.cn>
Cc: "H. Peter Anvin" <hpa@zytor.com>

arch/openrisc/kernel/prom.c

@@ -76,7 +76,6 @@ void __init early_init_devtree(void *params)
 	of_scan_flat_dt(early_init_dt_scan_chosen, cmd_line);
 
 	/* Scan memory nodes and rebuild MEMBLOCKs */
-	memblock_init();
 	of_scan_flat_dt(early_init_dt_scan_root, NULL);
 	of_scan_flat_dt(early_init_dt_scan_memory, NULL);