cpu-set-util: add cpu_set_count() helper

Let's add a minor, simplifying helper for getting number of CPUs in a
mask.

src/shared/cpu-set-util.h

@@ -38,3 +38,11 @@ int cpu_set_to_dbus(const CPUSet *c, uint8_t **ret, size_t *ret_size);
 int cpu_set_from_dbus(const uint8_t *bits, size_t size, CPUSet *ret);
 
 int cpus_in_affinity_mask(void);
+
+static inline size_t cpu_set_count(const CPUSet *c) {
+        if (!c)
+                return 0;
+        if (c->allocated <= 0)
+                return 0;
+        return CPU_COUNT_S(c->allocated, c->set);
+}

src/shared/numa-util.c

@@ -26,7 +26,7 @@ bool numa_policy_is_valid(const NUMAPolicy *policy) {
 
         if (policy->nodes.set &&
             numa_policy_get_type(policy) == MPOL_PREFERRED &&
-            CPU_COUNT_S(policy->nodes.allocated, policy->nodes.set) != 1)
+            cpu_set_count(&policy->nodes) != 1)
                 return false;
 
         return true;

src/test/test-cpu-set-util.c

@@ -11,7 +11,8 @@
 #define ASSERT_CPUSET_COUNT(c, n)                                       \
         ASSERT_NOT_NULL(c.set);                                         \
         ASSERT_GE(c.allocated, CPU_ALLOC_SIZE(n));                      \
-        ASSERT_EQ(CPU_COUNT_S(c.allocated, c.set), (n))
+        ASSERT_EQ(CPU_COUNT_S(c.allocated, c.set), (n));                \
+        ASSERT_EQ(cpu_set_count(&c), (size_t) (n))
 
 #define ASSERT_CPUSET_ISSET(c, i)                               \
         ASSERT_TRUE(CPU_ISSET_S(i, c.allocated, c.set));