Change order independant push logic to not change behavior.

Since redisGetReplyFromReader is exposed in a header file, we probably
shouldn't modify how it behaves in any way.  For this reason, handle the
changed logic in an internal static helper method.

hiredis.c

@@ -1005,14 +1005,23 @@ static int redisHandledPushReply(redisContext *c, void *reply) {
     return 0;
 }
 
-/* Internal helper function to try and get a reply from the reader,
- * or set an error in the context otherwise. */
+/* Get a reply from our reader or set an error in the context. */
 int redisGetReplyFromReader(redisContext *c, void **reply) {
+    if (redisReaderGetReply(c->reader, reply) == REDIS_ERR) {
+        __redisSetError(c,c->reader->err,c->reader->errstr);
+        return REDIS_ERR;
+    }
+
+    return REDIS_OK;
+}
+
+/* Internal helper to get the next reply from our reader while handling
+ * any PUSH messages we encounter along the way.  This is separate from
+ * redisGetReplyFromReader so as to not change its behavior. */
+static int redisNextInBandReplyFromReader(redisContext *c, void **reply) {
     do {
-        if (redisReaderGetReply(c->reader,reply) == REDIS_ERR) {
-            __redisSetError(c,c->reader->err,c->reader->errstr);
+        if (redisGetReplyFromReader(c, reply) == REDIS_ERR)
             return REDIS_ERR;
-        }
     } while (redisHandledPushReply(c, *reply));
 
     return REDIS_OK;
@@ -1023,7 +1032,7 @@ int redisGetReply(redisContext *c, void **reply) {
     void *aux = NULL;
 
     /* Try to read pending replies */
-    if (redisGetReplyFromReader(c,&aux) == REDIS_ERR)
+    if (redisNextInBandReplyFromReader(c,&aux) == REDIS_ERR)
         return REDIS_ERR;
 
     /* For the blocking context, flush output buffer and read reply */
@@ -1039,7 +1048,7 @@ int redisGetReply(redisContext *c, void **reply) {
             if (redisBufferRead(c) == REDIS_ERR)
                 return REDIS_ERR;
 
-            if (redisGetReplyFromReader(c,&aux) == REDIS_ERR)
+            if (redisNextInBandReplyFromReader(c,&aux) == REDIS_ERR)
                 return REDIS_ERR;
         } while (aux == NULL);
     }