fix for build error in test_cic.cpp (windows)

[guruofquality]

> C:\projects\LimeSDR\pothos\spuce\test_spuce\test_cic.cpp(23): error C2220: 
> warning treated as error - no 'object' file generated
> C:\projects\LimeSDR\pothos\spuce\test_spuce\test_cic.cpp(23): warning 
> C4800: 'signed char': forcing value to bool 'true' or 'false' (performance 
> warning)
> 
> I have fixed changing in .\pothos\spuce\test_spuce\test_cic.cpp 
>         signed char dump = 1;
> into 
>         bool dump = 1;

• reference: https://groups.google.com/forum/#!topic/pothos-users/-fpnpzjl8_Q