Kernel: Add copy_typed_from_user for non-const Userspace<T*>

Author: https://github.com/supercomputer7
Commit: d69a0380e1
Pull-request: https://github.com/SerenityOS/serenity/pull/15895
Reviewed-by: https://github.com/ADKaster ✅
Reviewed-by: https://github.com/LucasChollet
Reviewed-by: https://github.com/tslater2006

Kernel/StdLib.h

@@ -171,3 +171,11 @@ inline ErrorOr<T> copy_typed_from_user(Userspace<T const*> user_data)
     TRY(copy_from_user(&data, user_data));
     return data;
 }
+
+template<typename T>
+inline ErrorOr<T> copy_typed_from_user(Userspace<T*> user_data)
+{
+    T data {};
+    TRY(copy_from_user(&data, user_data));
+    return data;
+}