Get rid of unitialised variable warning when it's false.

cgminer.c

@@ -2037,12 +2037,14 @@ static void push_curl_entry(struct curl_ent *ce, struct pool *pool)
 	mutex_unlock(&pool->pool_lock);
 }
 
+/* ce and pool may appear uninitialised at push_curl_entry, but they're always
+ * set when we don't have opt_benchmark enabled */
 static void *get_work_thread(void *userdata)
 {
 	struct workio_cmd *wc = (struct workio_cmd *)userdata;
+	struct curl_ent * uninitialised_var(ce);
+	struct pool * uninitialised_var(pool);
 	struct work *ret_work = make_work();
-	struct curl_ent *ce;
-	struct pool *pool;
 	int failures = 0;
 
 	pthread_detach(pthread_self());

miner.h

@@ -122,6 +122,8 @@ void *alloca (size_t);
 #endif
 #define __maybe_unused		__attribute__((unused))
 
+#define uninitialised_var(x) x = x
+
 #if defined(__i386__)
 #define WANT_CRYPTOPP_ASM32
 #endif