std.event: use .{} to initiate Lock to unlocked state

Co-authored-by: Mikko Kaihlavirta <kaihlavirta@gmail.com>

lib/std/event/group.zig

@@ -35,7 +35,7 @@ pub fn Group(comptime ReturnType: type) type {
             return Self{
                 .frame_stack = Stack.init(),
                 .alloc_stack = AllocStack.init(),
-                .lock = Lock.init(),
+                .lock = .{},
                 .allocator = allocator,
             };
         }

lib/std/event/locked.zig

@@ -22,7 +22,7 @@ pub fn Locked(comptime T: type) type {
 
         pub fn init(data: T) Self {
             return Self{
-                .lock = Lock.init(),
+                .lock = .{},
                 .private_data = data,
             };
         }