Revert "Simplify STARPU_UNLIKELY expressions"

This reverts commit 277d888c3513cb12eff828e02f71e0c40b9352c3.

It was producing warnings with pointers

include/starpu_util.h

@@ -61,7 +61,7 @@ extern "C"
    expression as unlikely.
 */
 #ifdef __GNUC__
-#  define STARPU_UNLIKELY(expr)          (__builtin_expect((expr),0))
+#  define STARPU_UNLIKELY(expr)          (__builtin_expect(!!(expr),0))
 #else
 #  define STARPU_UNLIKELY(expr)          (expr)
 #endif