Tweak valgrind suppressions for intentional leaks.

tools/valgrind.supp

 # Pass this file to Valgrind with "--suppressions=tools/valgrind.supp"
 
 # Intentional thread / memory leak in DM.
 {
    dm_keepalive_thread_leak
    Memcheck:Leak
    match-leak-kinds: possible
    ...
    fun:_ZN8SkThreadC1EPFvPvES0_
    ...
    fun:_Z7dm_mainv
-   fun:main
+   ...
 }
 
 # Intentional thread / memory leak in nanobench.
 {
    nanobench_keepalive_thread_leak
    Memcheck:Leak
    match-leak-kinds: possible
    ...
    fun:_ZN8SkThreadC1EPFvPvES0_
    ...
    fun:_Z14nanobench_mainv
-   fun:main
+   ...
 }
 
 # Third party lib, driver issues.
 {
     ati_driver_bug_1
     Memcheck:Param
     ioctl(generic)
     fun:ioctl
     ...
     obj:/usr/lib/x86_64-linux-gnu/dri/fglrx_dri.so
@@ skipping 224 matching lines @@
     Memcheck:Cond
     fun:_ZL15S32A_D565_BlendPtPKjijii
     fun:_ZN26Sprite_D16_S32_BlitRowProc8blitRectEiiii
 }
 {
     libjpeg_turbo_bug4550_3
     Memcheck:Cond
     fun:_ZN12_GLOBAL__N_120ConvolveHorizontallyILb0EEEvPKhRK21SkConvolutionFilter1DPh
     fun:_Z14BGRAConvolve2DPKhibRK21SkConvolutionFilter1DS3_iPhRK18SkConvolutionProcsb
 }