monitor: Clean up HMP gdbserver error reporting

HMP command gdbserver used to emit two error messages for certain
errors.  For instance, with -M none:

    (qemu) gdbserver
    gdbstub: meaningless to attach gdb to a machine without any CPU.
    Could not open gdbserver on device 'tcp::1234'

The first message is the specific error, and the second one a generic
additional message that feels superfluous to me.

Commit c0e6b8b798b (system: propagate Error to gdbserver_start (and
other device setups)) turned the first message into a warning:

    warning: gdbstub: meaningless to attach gdb to a machine without any CPU.
    Could not open gdbserver on device 'tcp::1234'

This is arguably worse.

hmp_gdbserver() passes &error_warn to gdbserver_start(), so that
failure gets reported as warning, and then additionally emits the
generic error on failure.  This is a misuse of &error_warn.

Instead, receive the error in &err and report it, as usual.  With
this, gdbserver reports just the error:

    gdbstub: meaningless to attach gdb to a machine without any CPU.

Cc: Alex Bennée <alex.bennee@linaro.org>
Signed-off-by: Markus Armbruster <armbru@redhat.com>
Reviewed-by: Daniel P. Berrangé <berrange@redhat.com>
Message-ID: <20250923091000.3180122-2-armbru@redhat.com>
Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Akihiko Odaki <odaki@rsg.ci.i.u-tokyo.ac.jp>

0 files changed, 0 insertions, 0 deletions