devtools: ignore warning on long log string

devtools: ignore warning on long log string

The checkpatch.pl tool is flagging warnings on long debug log strings.
Since splitting these strings makes it difficult to search for logs it is
preferred to allow these as exceptions to the long line rule.  The addition
of the LONG_LINE_STRINGS to the list of exceptions will allow lines that
end with a string to exceed the maximum line length, but lines that end
with variables or other constructs will still be flagged as errors.  Also,
lines that make use of PRIx64 with string concatenation will still be
flagged if the beginning of the last string fragment begins after the 80
character threshold.

Signed-off-by: Allain Legacy <allain.legacy@windriver.com>