rauc.t: fix rauc test command chaining
rauc.t: fix rauc test command chaining

Commands must be chained with `&&` in order to let the tests fail
correctly in case of an error. Otherwise the error code of the
previously executed command would be overwritten by the next.

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

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