lguest: map_switcher_in_guest() per-vcpu

The switcher needs to be mapped per-vcpu, because different vcpus
will potentially have different page tables (they don't have to,
because threads will share the same).

So our first step is the make the function receive a vcpu struct

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/drivers/lguest/x86/core.c b/drivers/lguest/x86/core.c
index 66f48fc..d35f629 100644
--- a/drivers/lguest/x86/core.c
+++ b/drivers/lguest/x86/core.c
@@ -91,7 +91,7 @@
 	pages->state.host_cr3 = __pa(current->mm->pgd);
 	/* Set up the Guest's page tables to see this CPU's pages (and no
 	 * other CPU's pages). */
-	map_switcher_in_guest(lg, pages);
+	map_switcher_in_guest(cpu, pages);
 	/* Set up the two "TSS" members which tell the CPU what stack to use
 	 * for traps which do directly into the Guest (ie. traps at privilege
 	 * level 1). */