Suppress performance-avold-endl clang-tidy warning

This is a new warning introduced in clang-r498229.

Bug: 285005947
Test: build
Change-Id: Ia66c1f2555e2654614137e950832070e4e8dd54f
diff --git a/cc/config/tidy.go b/cc/config/tidy.go
index d55a13d..2e7832e 100644
--- a/cc/config/tidy.go
+++ b/cc/config/tidy.go
@@ -42,6 +42,8 @@
 		"-bugprone-unchecked-optional-access",
 		// http://b/265438407
 		"-misc-use-anonymous-namespace",
+		// http://b/285005947
+		"-performance-avoid-endl",
 	}
 
 	// Some clang-tidy checks are included in some tidy_checks_as_errors lists,