Suppress memcheck errors on linux bot.

tools/valgrind-webrtc/memcheck/suppressions.txt

 # This file is used in addition to the one already maintained in Chrome.
 # It acts as a place holder for future additions for WebRTC.
 # It must exist for the Python wrapper script to work properly.
 
 # There are three kinds of suppressions in this file.
 # 1. third_party libraries
 # 2. webrtc stuff
 # 3. libjingle stuff (talk folder)
 #-----------------------------------------------------------------------
 
@@ skipping 245 matching lines @@
    fun:WebRtcNetEQ_RecOut
    ...
 }
 
 {
    bug_270_2
    Memcheck:Uninitialized
    fun:WebRtcNetEQ_GetSpeechOutputType
    ...
 }
+{
+   vfprintf
+   Memcheck:Uninitialized
+   fun:vfprintf
+   fun:vsnprintf
+   fun:snprintf
+   ...
+   fun:_ZNK7testing8internal18FunctionMockerBaseIFbRKN6webrtc4rtcp17TransportFeedbackEEE32UntypedDescribeUninterestingCallEPKvPSo
+   fun:_ZN7testing8internal25UntypedFunctionMockerBase17UntypedInvokeWithEPKv
+   fun:_ZN6webrtc11MockRtpRtcp18SendFeedbackPacketERKNS_4rtcp17TransportFeedbackE
+   fun:_ZN6webrtc12PacketRouter12SendFeedbackEPNS_4rtcp17TransportFeedbackE
+   fun:_ZN6webrtc34PacketRouterTest_SendFeedback_Test8TestBodyEv
+}
+
 
 #-----------------------------------------------------------------------
 # libjingle stuff (talk folder)
 {
    bug_2056_1
    Memcheck:Leak
    fun:malloc
    fun:_dl_close_worker
    fun:_dl_close
    fun:_dl_catch_error
@@ skipping 160 matching lines @@
    fun:_ZN3rtc12_GLOBAL__N_122CreateClientConnectionERNS_10HttpServerERNS0_17HttpServerMonitorEb
    fun:_ZN3rtc47HttpServer_SignalsCloseAfterForcedCloseAll_Test8TestBodyEv
 }
 {
    bug_5989
    Memcheck:Unaddressable
    ...
    fun:_ZNK3rtc15CriticalSection5EnterEv
    ...
 }