A few fixes in locore.S

[Maxime Villard <max%m00nbsd.net@localhost>]

There's a strange comment in amd64/locore.S that says this:

	/*
	 * Load parameters from the stack (32 bits):
	 *     boothowto, [bootdev], bootinfo, esym, biosbasemem, biosextmem
	 * We are not interested in 'bootdev'.
	 */

But you can see in the code that biosextmem is retrieved here

	movl	20(%esp),%eax

and biosbasemem here

	movl	24(%esp),%eax

I guess the comment should be

	boothowto, [bootdev], bootinfo, esym, biosextmem, biosbasemem

right?

Also:

Index: locore.S
===================================================================
RCS file: /cvsroot/src/sys/arch/amd64/amd64/locore.S,v
retrieving revision 1.83
diff -u -r1.83 locore.S
--- locore.S	25 Nov 2015 16:00:09 -0000	1.83
+++ locore.S	11 Dec 2015 18:02:52 -0000
@@ -427,7 +427,7 @@

    	movl	(%ecx),%eax		/* size of entry */
    	movl	%edx,%edi
-	addl	(%ecx),%edx		/* update dest pointer */
+	addl	%eax,%edx		/* update dest pointer */
    	cmpl	%ebp,%edx		/* beyond bootinfo+BOOTINFO_MAXSIZE? */
    	jg	bootinfo_overflow

right?

thanks