During device memory memset, the driver allocates and use a CB (command
buffer). To reuse existing code, it keeps a pointer to the CB in two
variables, user_cb and patched_cb. Therefore, there is no need to "put"
both the user_cb and patched_cb, as it will cause an underflow of the
refcnt of the CB.
Signed-off-by: Oded Gabbay <oded.gabbay@gmail.com>