classes/buildhistory: fix filtering of depends-nokernel.dot
For images we produce a number of filtered dependency .dot files for
readability, the first of which is depends-nokernel.dot which filters
out just the kernel itself (not kernel modules). Unfortunately the
filter specifications hadn't been updated for the dash-to-underscore
removal or the 4.x kernel upgrade, thus the filtering wasn't actually
doing anything.
Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com> Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
