xlnx_dp: drop unsupported AUXCommand in xlnx_dp_aux_set_command

In xlnx_dp_aux_set_command, when the command leads to the default
branch, xlxn-dp will abort and then crash.

This patch removes this abort and drops this operation.

Fixes: 58ac482 ("introduce xlnx-dp")
Resolves: https://gitlab.com/qemu-project/qemu/-/issues/411
Reported-by: Qiang Liu <cyruscyliu@gmail.com>
Tested-by: Qiang Liu <cyruscyliu@gmail.com>
Suggested-by: Thomas Huth <thuth@redhat.com>
Signed-off-by: Qiang Liu <cyruscyliu@gmail.com>
Reviewed-by: Thomas Huth <thuth@redhat.com>
Reviewed-by: Frederic Konrad <fkonrad@amd.com>
Message-Id: <20220808080116.2184881-1-cyruscyliu@gmail.com>
Signed-off-by: Laurent Vivier <laurent@vivier.eu>
diff --git a/hw/display/xlnx_dp.c b/hw/display/xlnx_dp.c
index a071c81..b0828d6 100644
--- a/hw/display/xlnx_dp.c
+++ b/hw/display/xlnx_dp.c
@@ -532,8 +532,8 @@
         qemu_log_mask(LOG_UNIMP, "xlnx_dp: Write i2c status not implemented\n");
-        error_report("%s: invalid command: %u", __func__, cmd);
-        abort();
+        qemu_log_mask(LOG_GUEST_ERROR, "%s: invalid command: %u", __func__, cmd);
+        return;
     s->core_registers[DP_INTERRUPT_SIGNAL_STATE] |= 0x04;