cpumask: remove x86 cpumask_t uses.

Impact: cleanup

We are removing cpumask_t in favour of struct cpumask: mainly as a
marker of what code is now CONFIG_CPUMASK_OFFSTACK-safe.

The only non-trivial change here is vector_allocation_domain():
explicitly clear the mask and set the first word, rather than using
assignment.

Signed-off-by: Rusty Russell <rusty@rustcorp.com.au>
diff --git a/arch/x86/include/asm/topology.h b/arch/x86/include/asm/topology.h
index 1ce1e1a..e3f4198 100644
--- a/arch/x86/include/asm/topology.h
+++ b/arch/x86/include/asm/topology.h
@@ -89,7 +89,7 @@
 extern cpumask_var_t node_to_cpumask_map[MAX_NUMNODES];
 
 #ifdef CONFIG_DEBUG_PER_CPU_MAPS
-extern const cpumask_t *cpumask_of_node(int node);
+extern const struct cpumask *cpumask_of_node(int node);
 #else
 /* Returns a pointer to the cpumask of CPUs on Node 'node'. */
 static inline const struct cpumask *cpumask_of_node(int node)
@@ -172,7 +172,7 @@
 	return 0;
 }
 
-static inline const cpumask_t *cpumask_of_node(int node)
+static inline const struct cpumask *cpumask_of_node(int node)
 {
 	return cpu_online_mask;
 }