Fix a broken boolean test found by clang.

This was only on the failure case, so this probably never caused
any real trouble.

Change-Id: Id983689772102cbb9171693b927e544fb0b584fb
diff --git a/libc/bionic/malloc_debug_common.cpp b/libc/bionic/malloc_debug_common.cpp
index cbca160..9399237 100644
--- a/libc/bionic/malloc_debug_common.cpp
+++ b/libc/bionic/malloc_debug_common.cpp
@@ -408,7 +408,7 @@
     dlclose(malloc_impl_handle);
     return;
   }
-  if (malloc_debug_initialize(&g_hash_table) == -1) {
+  if (!malloc_debug_initialize(&g_hash_table)) {
     dlclose(malloc_impl_handle);
     return;
   }