crypto: atmel-sha204a - Fix potential UAF and memory leak in remove path

crypto: atmel-sha204a - Fix potential UAF and memory leak in remove path

Unregister the hwrng to prevent new ->read() calls and flush the Atmel
I2C workqueue before teardown to prevent a potential UAF if a queued
callback runs while the device is being removed.

Drop the early return to ensure sysfs entries are removed and
->hwrng.priv is freed, preventing a memory leak.

Fixes: da001fb651b0 ("crypto: atmel-i2c - add support for SHA204A random number generator")
Cc: stable@vger.kernel.org
Signed-off-by: Thorsten Blum <thorsten.blum@linux.dev>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>