Revert "rust: lock: guard: Add T: Unpin bound to DerefMut"

This reverts commit da123f0.

Author: jannau

rust/kernel/sync/lock.rs

@@ -281,10 +281,7 @@ impl<T: ?Sized, B: Backend> core::ops::Deref for Guard<'_, T, B> {
     }
 }
 
-impl<T: ?Sized, B: Backend> core::ops::DerefMut for Guard<'_, T, B>
-where
-    T: Unpin,
-{
+impl<T: ?Sized, B: Backend> core::ops::DerefMut for Guard<'_, T, B> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         // SAFETY: The caller owns the lock, so it is safe to deref the protected data.
         unsafe { &mut *self.lock.data.get() }

rust/kernel/sync/lock/global.rs

@@ -106,10 +106,7 @@ impl<B: GlobalLockBackend> core::ops::Deref for GlobalGuard<B> {
     }
 }
 
-impl<B: GlobalLockBackend> core::ops::DerefMut for GlobalGuard<B>
-where
-    B::Item: Unpin,
-{
+impl<B: GlobalLockBackend> core::ops::DerefMut for GlobalGuard<B> {
     fn deref_mut(&mut self) -> &mut Self::Target {
         &mut self.inner
     }