hmp: fix snapshot_blkdev argument type

The `snapshot-file` argument for `snapshot_blkdev` is mandatory. Correct
the `args_type` definition to reflect this.

Fixes: 6106e2492f ("qapi: Convert blockdev_snapshot_sync")
Reviewed-by: Philippe Mathieu-Daudé <philmd@oss.qualcomm.com>
Signed-off-by: Marc-André Lureau <marcandre.lureau@redhat.com>
Message-ID: <20260828-qemu-no-hmp-v5-4-9227de146347@redhat.com>

block/monitor/block-hmp-cmds.c

@@ -344,25 +344,15 @@ void hmp_block_job_complete(Monitor *mon, const QDict *qdict)
 void hmp_snapshot_blkdev(Monitor *mon, const QDict *qdict)
 {
     const char *device = qdict_get_str(qdict, "device");
-    const char *filename = qdict_get_try_str(qdict, "snapshot-file");
+    const char *filename = qdict_get_str(qdict, "snapshot-file");
     const char *format = qdict_get_try_str(qdict, "format");
     bool reuse = qdict_get_try_bool(qdict, "reuse", false);
     enum NewImageMode mode;
     Error *err = NULL;
 
-    if (!filename) {
-        /*
-         * In the future, if 'snapshot-file' is not specified, the snapshot
-         * will be taken internally. Today it's actually required.
-         */
-        error_setg(&err, QERR_MISSING_PARAMETER, "snapshot-file");
-        goto end;
-    }
-
     mode = reuse ? NEW_IMAGE_MODE_EXISTING : NEW_IMAGE_MODE_ABSOLUTE_PATHS;
     qmp_blockdev_snapshot_sync(device, NULL, filename, NULL, format,
                                true, mode, &err);
-end:
     hmp_handle_error(mon, err);
 }
 

hmp-commands.hx

@@ -1173,7 +1173,7 @@ ERST
 
     {
         .name       = "snapshot_blkdev",
-        .args_type  = "reuse:-n,device:B,snapshot-file:s?,format:s?",
+        .args_type  = "reuse:-n,device:B,snapshot-file:s,format:s?",
         .params     = "[-n] device [new-image-file] [format]",
         .help       = "initiates a live snapshot\n\t\t\t"
                       "of device. If a new image file is specified, the\n\t\t\t"