Kernel: Remove a comment that has been stale since 7a64f55c0f

Author: https://github.com/nico
Commit: https://github.com/SerenityOS/serenity/commit/96ff0971ead
Pull-request: https://github.com/SerenityOS/serenity/pull/3185

Kernel/Thread.cpp

@@ -614,9 +614,6 @@ void Thread::push_value_on_stack(FlatPtr value)
 
 RegisterState& Thread::get_register_dump_from_stack()
 {
-    // The userspace registers should be stored at the top of the stack
-    // We have to subtract 2 because the processor decrements the kernel
-    // stack before pushing the args.
     return *(RegisterState*)(kernel_stack_top() - sizeof(RegisterState));
 }