mkrockspecs: fix a typo.
mkrockspecs: fix a typo.

* src/mkrockspecs.in: Add missing 's' to spec.build.modules reset.

Signed-off-by: Gary V. Vaughan <f9023000f29773649f3850298becb9544b5fd6a9@gnu.org>

gvvaughan/slingshot