test_libvpx: fix valgrind failures
test_libvpx: fix valgrind failures

add an operator<<() for instances of
function_equivalence_test.h:FuncParam

Change-Id: Ifced8401443085bdbdccb97718564b0372b264b7

GrokImageCompression/aom,GrokImageCompression/aom,luctrudeau/aom,mbebenita/aom,smarter/aom,smarter/aom,luctrudeau/aom,GrokImageCompression/aom,mbebenita/aom,mbebenita/aom,luctrudeau/aom,mbebenita/aom,mbebenita/aom,mbebenita/aom,GrokImageCompression/aom,smarter/aom,mbebenita/aom,mbebenita/aom,luctrudeau/aom,GrokImageCompression/aom,GrokImageCompression/aom,luctrudeau/aom,smarter/aom,mbebenita/aom,smarter/aom,smarter/aom,luctrudeau/aom