suppress su behavior when running lsof

Relevant error logs show up when dumpstate do lsof using su identity:
RunCommand("LIST OF OPEN FILES", {"lsof"}, CommandOptions::AS_ROOT);

This is an intended behavior and the log is useless for debugging so I
suppress them.
Bug: 226717429
Test: do bugreport with relevant error gone.
Change-Id: Ide03315c1189ae2cbfe919566e6b97341c5991bb
1 file changed