lguest: replace lguest_arch with lg_cpu_arch.

The fields found in lguest_arch are not really per-guest,
but per-cpu (gdt, idt, etc). So this patch turns lguest_arch
into lg_cpu_arch.

It makes sense to have a per-guest per-arch struct, but this
can be addressed later, when the need arrives.

Signed-off-by: Glauber de Oliveira Costa <gcosta@redhat.com>
Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/include/asm-x86/lguest.h b/include/asm-x86/lguest.h
index ccd3384..b9d003b 100644
--- a/include/asm-x86/lguest.h
+++ b/include/asm-x86/lguest.h
@@ -56,7 +56,7 @@
 	struct desc_struct guest_gdt[GDT_ENTRIES];
 };
 
-struct lguest_arch
+struct lg_cpu_arch
 {
 	/* The GDT entries copied into lguest_ro_state when running. */
 	struct desc_struct gdt[GDT_ENTRIES];