tools/wltests: lets --help report a usable example command line
tools/wltests: lets --help report a usable example command line

Signed-off-by: Patrick Bellasi <431c86f368affbc3148c4669fbd465131f7e82cb@arm.com>

ARM-software/lisa,credp/lisa,credp/lisa,ARM-software/lisa,credp/lisa,ARM-software/lisa,bjackman/lisa,ARM-software/lisa,credp/lisa,bjackman/lisa