valgrind: updated suppressions file

The call stack was modified in 2dc7ad23 so the supressions didn't work
anymore.

tests/valgrind.supp

@@ -13,6 +13,7 @@
    fun:easy_transfer
    fun:easy_perform
    fun:curl_easy_perform
+   fun:operate_do
    fun:operate
    fun:main
 }
@@ -34,6 +35,7 @@
    fun:easy_events
    fun:easy_perform
    fun:curl_easy_perform_ev
+   fun:operate_do
    fun:operate
    fun:main
 }