Make topology checkers to check the return value of strbuf APIs so that
it can detect errors in it.
Signed-off-by: Masami Hiramatsu <mhiramat@kernel.org>
Cc: Namhyung Kim <namhyung@kernel.org>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/20160510054735.6158.98650.stgit@devbox
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>