Drop the unused  parameter from log_message() / CI_Log::write_log()
diff --git a/tests/mocks/core/common.php b/tests/mocks/core/common.php
index 0ccfe1e..e5dc29c 100644
--- a/tests/mocks/core/common.php
+++ b/tests/mocks/core/common.php
@@ -178,7 +178,7 @@
 
 if ( ! function_exists('log_message'))
 {
-	function log_message($level, $message, $php_error = FALSE)
+	function log_message($level, $message)
 	{
 		return TRUE;
 	}