rust: i2c: fix I2cAdapter refcount double increment

A single bugfix for the Rust I2C abstractions, targeting 7.1.
 
 `I2cAdapter::get` calls `i2c_get_adapter()` which returns a pointer with
 an already-incremented refcount. The code then converts the raw pointer to
 an `ARef` via `.into()`, which calls `inc_ref()` again through the
 `From<&T> for ARef<T>` impl — resulting in a leaked device and module
 reference on every call.
 
 The fix uses `ARef::from_raw()` instead, which takes ownership of the
 existing refcount without incrementing it.
 
 Signed-off-by: Igor Korotin <igor.korotin@linux.dev>
 -----BEGIN PGP SIGNATURE-----
 
 iQIzBAABCgAdFiEEG0Kepq7dYk2deNuvoxQiWQ2T6tUFAmokUrYACgkQoxQiWQ2T
 6tXfcw//SeqQ76PJjSQf1DKf7uTEgR73RZIVEEAWEYaABPOVmwZpIAniqMz+Np2s
 CBNVpttdcbgjCsbxQny9zbgCbeOGbexP2sMEuugjxDYwXAHo5OFnY3q0ReJVQIGa
 I6HB38lQpK1+p20W+CzqH7TIT5Tj7VOCpuIRu86lMUVTFVAgJSW8VMGkKqjO7ler
 VshMUQe8SJaIxC6XAj1ChsELfHptJozZw7zUZhj2wCmfs+pl43onE079DqNfxQJ8
 YWgaF3oSBxh2/CFORJKpCy5S7J4P6JQ4j0U8G7Gvs01lhnXggPewA0oJTQlpfNPj
 UGKLnSo9pG0BdGcxFqiPKqfxrAq29LO776IcrRSQa7sEcSlwRh4L4h0LFY0TUvmY
 5nR5BoXLOYpmrNP7WFCUISvjVXJaX8F3MEnVC7R/PmnOUhXWLBXZyzqzgUrAPkgl
 R4Ofye3yWpdJRes4O7diR3vnvRdxLMpfehJi2WHUjB90StxrLkYGZRK5fGj6+90m
 Pmefu7Qic1mos5jy0/9UjfaIaUS1W23KxX8HcNoMLZF/tl8YJ1FtMpm6ZrRSxM/v
 1LiEXLZkQOfuNebjfyUZwzWIptYtq9h4N9X9ANykLPTiTncJmxQmzaPsoRE4ew0T
 AD7P/WpLFbLs2XI/J5JuAVrfnOe+UjnvsixBxuPxEtgVY5K2pjA=
 =LhTi
 -----END PGP SIGNATURE-----

Merge tag 'rust-i2c-7.1-rc7' of https://github.com/ikrtn/linux into i2c/for-current

rust: i2c: fix I2cAdapter refcount double increment

rust/kernel/i2c.rs

@@ -405,7 +405,9 @@ impl I2cAdapter {
 
         // SAFETY: `adapter` is non-null and points to a live `i2c_adapter`.
         // `I2cAdapter` is #[repr(transparent)], so this cast is valid.
-        Ok(unsafe { (&*adapter.as_ptr().cast::<I2cAdapter<device::Normal>>()).into() })
+        // `i2c_get_adapter` returned the adapter with an incremented refcount, which we pass to
+        // the `ARef`.
+        Ok(unsafe { ARef::from_raw(adapter.cast::<I2cAdapter<device::Normal>>()) })
     }
 }