Update the line number for a couple cppcheck suppressions and add one for
the pool variable in the vvp directory.
Also move a check for null to the correct place.
The files we get from GTKWave are not under our control so we need to
ignore the cppcheck style warnings for them. The random routines are
from the standard so they should not be changed to fix style warnings
either. We also have some weird, but correct pointer subtraction that
cppcheck warns about. This patch adds suppression files for all these
warnings. You must have the latest cppcheck from git since I submitted
a patch that adds the ability to place comments in the suppression file.