Minor grammar correction along with making the term 'login banner'
consistent throughout to make searching logs easier.
(From OE-Core rev: 54e739485faba8d80f5af15407905aaeda4767f4)
Signed-off-by: Mark Asselstine <mark.asselstine@windriver.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>