valgrind.supp: tweaked a test 165 suppression

A recent change seems to have slightly changed the call stack
produced by the gcc optimizer.

tests/valgrind.supp

@@ -67,7 +67,7 @@
    fun:multi_runsingle
    fun:curl_multi_perform
    fun:easy_perform
-   fun:operate_do
+   fun:operate_do.isra.0
    fun:operate
    fun:main
 }