libdl.cpp doesn't need <stdbool.h> like libdl.c did.

Bug: N/A
Test: builds
Change-Id: I2f43fa60c8128b2b40de63748b5568fa4c9e351d
diff --git a/libdl/libdl.cpp b/libdl/libdl.cpp
index 97cdeb4..c834088 100644
--- a/libdl/libdl.cpp
+++ b/libdl/libdl.cpp
@@ -17,7 +17,6 @@
 #include <dlfcn.h>
 #include <link.h>
 #include <stdlib.h>
-#include <stdbool.h>
 #include <android/dlext.h>
 
 // These functions are exported by the loader