target/s390x/cpu_model: Make check_compatibility() return boolean

As error.h suggested, the best practice for callee is to return
something to indicate success / failure.

With returned boolean, there's no need to check @err.

Suggested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Zhao Liu <zhao1.liu@intel.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Message-ID: <20240425031232.1586401-2-zhao1.liu@intel.com>
Signed-off-by: Thomas Huth <thuth@redhat.com>
1 file changed