libinput-config: fix set_accel_speed type

This should have always been a double. This is a bit awkward as it
breaks existing users but the protocol specifies a double and this
is clearly a river bug/typo.

 river/LibinputDevice.zig | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/river/LibinputDevice.zig b/river/LibinputDevice.zig
index a2a15ef..c6d716d 100644
--- a/river/LibinputDevice.zig
+++ b/river/LibinputDevice.zig
@@ -329,11 +329,11 @@ fn handleRequest(
             }
         },
         .set_accel_speed => |args| {
-            if (args.speed.size != @sizeOf(f32)) {
+            if (args.speed.size != @sizeOf(f64)) {
                 object.postError(.invalid_arg, "invalid accel speed");
                 return;
             }
-            const speed = args.speed.slice(f32)[0];
+            const speed = args.speed.slice(f64)[0];
             const result = Result.create(object, args.result) orelse return;
             const status = c.libinput_device_config_accel_set_speed(device.libinput, speed);
             if (result.send(status)) {