rust: miscdevice: set fops.owner from driver module pointer

Set the miscdevice fops owner field from the driver module pointer
via the `this_module::<T::OwnerModule>()` helper, instead of
defaulting to null.

Assisted-by: opencode:glm-5.2
Reviewed-by: Andreas Hindborg <a.hindborg@kernel.org>
Reviewed-by: Gary Guo <gary@garyguo.net>
Acked-by: Danilo Krummrich <dakr@kernel.org>
Acked-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Alice Ryhl <aliceryhl@google.com>
Signed-off-by: Alvin Sun <alvin.sun@linux.dev>
Link: https://patch.msgid.link/20260811-fix-fops-owner-v10-6-7e71776f9dbe@linux.dev
Signed-off-by: Miguel Ojeda <ojeda@kernel.org>

rust/kernel/miscdevice.rs

@@ -24,12 +24,13 @@
         IovIterSource, //
     },
     mm::virt::VmaNew,
+    module::this_module,
     prelude::*,
     seq_file::SeqFile,
     types::{
         ForeignOwnable,
         Opaque, //
-    },
+    }, //
 };
 use core::marker::PhantomData;
 
@@ -430,6 +431,7 @@ impl<T: MiscDevice> MiscdeviceVTable<T> {
         } else {
             None
         },
+        owner: this_module::<T::OwnerModule>().as_ptr(),
         ..pin_init::zeroed()
     };