eina: fix eina_hash_stringshared_new to actually compute the hash on the pointer.

Before this patch, the key would always be zero and the hash would solely
rely on the rbtree to be efficient. This improve the situation by using the pointer
as the key during hash computation.

src/lib/eina/eina_hash.c

@@ -490,6 +490,12 @@ _eina_hash_del_by_key(Eina_Hash *hash, const void *key, const void *data)
    return _eina_hash_del_by_key_hash(hash, key, key_length, key_hash, data);
 }
 
+static int
+_eina_stringshared_hash(const void *key, int key_length EINA_UNUSED)
+{
+   return eina_hash_superfast(&key, sizeof (void*));
+}
+
 static unsigned int
 _eina_string_key_length(const char *key)
 {
@@ -846,7 +852,7 @@ eina_hash_stringshared_new(Eina_Free_Cb data_free_cb)
 {
    return eina_hash_new(NULL,
                         EINA_KEY_CMP(_eina_stringshared_key_cmp),
-                        EINA_KEY_HASH(eina_hash_superfast),
+                        EINA_KEY_HASH(_eina_stringshared_hash),
                         data_free_cb,
                         EINA_HASH_BUCKET_SIZE);
 }