pkg-stats: cnt should start with 0

The package count, cnt, should start with an initial value of 0.  It
is incremented as each package *.mk file is checked.  Starting with a
value of 1 makes the first ID = 2 and results in the TOTAL being off
by 1.

Signed-off-by: H Hartley Sweeten <hsweeten@visionengravers.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>