dm vdo memory-alloc: simplify allocations_allowed()

Signed-off-by: Mike Snitzer <snitzer@kernel.org>
Signed-off-by: Susan LeGendre-McGhee <slegendr@redhat.com>
Signed-off-by: Matthew Sakai <msakai@redhat.com>

drivers/md/dm-vdo/memory-alloc.c

@@ -20,11 +20,9 @@
  */
 static struct thread_registry allocating_threads;
 
-static bool allocations_allowed(void)
+static inline bool allocations_allowed(void)
 {
-	const bool *pointer = vdo_lookup_thread(&allocating_threads);
-
-	return (pointer != NULL) ? *pointer : false;
+	return vdo_lookup_thread(&allocating_threads) != NULL;
 }
 
 /*