[PATCH] initialise total_memory() earlier

[PATCH] initialise total_memory() earlier

Initialise total_memory earlier in boot.  Because if for some reason we run
page reclaim early in boot, we don't want total_memory to be zero when we use
it as a divisor.

And rename total_memory to vm_total_pages to avoid naming clashes with
architectures.

Cc: Yasunori Goto <[email protected]>
Cc: KAMEZAWA Hiroyuki <[email protected]>
Cc: Martin Bligh <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>
Signed-off-by: Linus Torvalds <[email protected]>