Removes the suppression rule for Bug 69906

This change removes the suppression rule for Bug 69906 because this leak seems to be fixed by r71641 <http://crrev.com/71641>. (Our heapchecker bots already works well without the suppressions for this bug.)

TBR=thestig,timurrrr 
BUG=69906
TEST=make the valgrind bots green without suppressions.
Review URL: http://codereview.chromium.org/6254008

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@71762 0039d316-1c4b-4281-b951-d872f2087c98

tools/valgrind/memcheck/suppressions.txt

@@ -3573,14 +3573,6 @@
    fun:_Znw*
    fun:_ZN28PrerenderResourceHandlerTestC2Ev
 }
-{
-   Bug_69906
-   Memcheck:Leak
-   fun:calloc
-   fun:speex_alloc
-   ...
-   fun:*SpeexEncoderC1Ei
-}
 {
    Bug_69919
    Memcheck:Leak