Revert "Issue/PR #3836"

This reverts commit 170ae282338584ebe257d2fb21101ccf84a3f800.
diff --git a/system/libraries/Cache/drivers/Cache_redis.php b/system/libraries/Cache/drivers/Cache_redis.php
index 773d20c..b940b76 100644
--- a/system/libraries/Cache/drivers/Cache_redis.php
+++ b/system/libraries/Cache/drivers/Cache_redis.php
@@ -165,9 +165,7 @@
 	 */
 	public function increment($id, $offset = 1)
 	{
-		return ($offset == 1)
-			? $this->_redis->incr($id)
-			: $this->_redis->incrBy($id, $offset);
+		return $this->_redis->incr($id, $offset);
 	}
 
 	// ------------------------------------------------------------------------
@@ -181,9 +179,7 @@
 	 */
 	public function decrement($id, $offset = 1)
 	{
-		return ($offset == 1)
-			? $this->_redis->decr($id)
-			: $this->_redis->decrBy($id, $offset);
+		return $this->_redis->decr($id, $offset);
 	}
 
 	// ------------------------------------------------------------------------