test/rauc.t: 'rauc checksum without argument' test not required
test/rauc.t: 'rauc checksum without argument' test not required

We basically test this with 'rauc missing arg' tests already.
Adapt them to explicitly test for return code 1.

Signed-off-by: Enrico Joerns <a2e5f936c390f36494e46e71bcfbe365bb1e8c49@pengutronix.de>

jluebbe/rauc,rauc/rauc,ejoerns/rauc,ejoerns/rauc,jluebbe/rauc,ejoerns/rauc,rauc/rauc,jluebbe/rauc,rauc/rauc