tc-testing: tdc.py: ignore errors when decoding stdout/stderr

[ Upstream commit 5aaf6428526bcad98d6f51f2f679c919bb75d7e9 ]

Prevent exceptions from being raised while decoding output
from an executed command. There is no impact on tdc's
execution and the verify command phase would fail the pattern
match.
Signed-off-by: NLucas Bates <lucasb@mojatatu.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>
Signed-off-by: NSasha Levin <sashal@kernel.org>

tools/testing/selftests/tc-testing/tdc.py

@@ -134,9 +134,9 @@ def exec_cmd(args, pm, stage, command):
     (rawout, serr) = proc.communicate()
 
     if proc.returncode != 0 and len(serr) > 0:
-        foutput = serr.decode("utf-8")
+        foutput = serr.decode("utf-8", errors="ignore")
     else:
-        foutput = rawout.decode("utf-8")
+        foutput = rawout.decode("utf-8", errors="ignore")
 
     proc.stdout.close()
     proc.stderr.close()