kexec/x86: do not map crash kernel area

This mapping was apparently never used.

Suggested-by: Jan Beulich <jbeulich@suse.com>
Signed-off-by: Daniel Kiper <daniel.kiper@oracle.com>
Acked-by: David Vrabel <david.vrabel@citrix.com>

xen/arch/x86/setup.c

@@ -1097,9 +1097,7 @@ void __init __start_xen(unsigned long mbi_p)
                          mod[i].mod_start,
                          PFN_UP(mod[i].mod_end), PAGE_HYPERVISOR);
     }
-    map_pages_to_xen((unsigned long)__va(kexec_crash_area.start),
-                     kexec_crash_area.start >> PAGE_SHIFT,
-                     PFN_UP(kexec_crash_area.size), PAGE_HYPERVISOR);
+
     xen_virt_end = ((unsigned long)_end + (1UL << L2_PAGETABLE_SHIFT) - 1) &
                    ~((1UL << L2_PAGETABLE_SHIFT) - 1);
     destroy_xen_mappings(xen_virt_end, XEN_VIRT_START + BOOTSTRAP_MAP_BASE);