optimus: fix boot hang, log buffer overrun

	* fix error in merge/port of PRINTK_PERSIST to optimus
	* if log previously wrapped (>8M), next boot would overrun log
		when initial boot log is copied to persistent one
	* possibly harmless unless previous log wrapped twice (>16M),
		then would cause hang (bad physical address access?)

Change-Id: I77f4bfa76486b9657e4e64b17efa65333e2932de
1 file changed