rpm: drop use of $FIRST_ARG

rpm: drop use of $FIRST_ARG

The use of $FIRST_ARG was probably required because the SUSE-specific
%service_* rpm macros were playing tricks on the shell positional parameters.
This is bad practice and error-prone, so let's assume that no macros should do
that anymore and hence it's safe to assume that positional parameters remain
unchanged after any rpm macro call.

Thanks to Franck Bui for providing this patch.

Signed-off-by: Nathan Cutler <ncutler@suse.com>