x86/apic/es7000+summit: Always make valid apicid from a cpumask

In case of invalid parameters cpu_mask_to_apicid_and() might
return apicid value of 0 (on Summit) or a uninitialized value
(on ES7000), although it is supposed to return apicid of cpu-0
at least. Fix the operation to always return a valid apicid.

Signed-off-by: Alexander Gordeev <agordeev@redhat.com>
Cc: Suresh Siddha <suresh.b.siddha@intel.com>
Cc: Yinghai Lu <yinghai@kernel.org>
Link: http://lkml.kernel.org/r/20120614075026.GH3383@dhcp-26-207.brq.redhat.com
Signed-off-by: Ingo Molnar <mingo@kernel.org>

arch/x86/kernel/apic/es7000_32.c

@@ -545,6 +545,8 @@ es7000_cpu_mask_to_apicid(const struct cpumask *cpumask, unsigned int *dest_id)
 		apicid = new_apicid;
 		round++;
 	}
+	if (!round)
+		return -EINVAL;
 	*dest_id = apicid;
 	return 0;
 }

arch/x86/kernel/apic/summit_32.c

@@ -282,6 +282,8 @@ summit_cpu_mask_to_apicid(const struct cpumask *cpumask, unsigned int *dest_id)
 		apicid |= new_apicid;
 		round++;
 	}
+	if (!round)
+		return -EINVAL;
 	*dest_id = apicid;
 	return 0;
 }