utils: Remove volatile qualifier from refcount_t typedef

It's not really required anymore (if it ever was) and may cause compiler
warnings when using the non atomic versions of ref_get/ref_put.

src/libstrongswan/utils/utils.h

@@ -656,8 +656,7 @@ static inline u_int64_t untoh64(void *network)
 /**
  * Special type to count references
  */
-typedef volatile u_int refcount_t;
+typedef u_int refcount_t;
-
 
 #ifdef HAVE_GCC_ATOMIC_OPERATIONS