(Normally hidden by T_LEXFLAGS containing -L in connectivity/Library_dbtools.mk
suppressing #line directives; some loplugin:literaltoboolconversion warning
would remain in a flex-provided occurrence of ECHO that is apparently not
properly prefixed by #line at least with flex 2.6.0.)
Change-Id: Id5693d6bd9e5b565dd9820e3cbea8e88e7967dd5