MINOR: pools: enable the fault injector in all allocation modes

The mem_should_fail() call enabled by DEBUG_FAIL_ALLOC used to be placed
only in the no-cache version of the allocator. Now we can generalize it
to all modes and remove the exclusive test on CONFIG_HAP_NO_GLOBAL_POOLS.
diff --git a/include/haproxy/pool-t.h b/include/haproxy/pool-t.h
index 4b185ef..073fe32 100644
--- a/include/haproxy/pool-t.h
+++ b/include/haproxy/pool-t.h
@@ -46,7 +46,7 @@
  * case we disable global pools. The global pools may still be enforced
  * using CONFIG_HAP_GLOBAL_POOLS though.
  */
-#if defined(USE_THREAD) && defined(HA_HAVE_FAST_MALLOC) && defined(CONFIG_HAP_POOLS) && !defined(CONFIG_HAP_GLOBAL_POOLS)
+#if defined(USE_THREAD) && defined(HA_HAVE_FAST_MALLOC) && !defined(CONFIG_HAP_GLOBAL_POOLS)
 #define CONFIG_HAP_NO_GLOBAL_POOLS
 #endif
 
diff --git a/src/pool.c b/src/pool.c
index b493a93..59cc508 100644
--- a/src/pool.c
+++ b/src/pool.c
@@ -156,6 +156,10 @@
 	int limit = pool->limit;
 	void *ptr = NULL;
 
+#ifdef DEBUG_FAIL_ALLOC
+	if (mem_should_fail(pool))
+		return NULL;
+#endif
 	if (limit && allocated >= limit) {
 		activity[tid].pool_fail++;
 		return NULL;
@@ -218,6 +222,10 @@
 	int limit = pool->limit;
 	int allocated = pool->allocated, allocated_orig = allocated;
 
+#ifdef DEBUG_FAIL_ALLOC
+	if (mem_should_fail(pool))
+		return NULL;
+#endif
 	/* stop point */
 	avail += pool->used;