eventdev/crypto: remove useless check

eventdev/crypto: remove useless check

eca_cryptodev_cdev_flush() is internal function and called with
valid range of cdevs.

crypto_cdev_info structure is allocated at adapter creation time
and retrieved from the adapter for a valid cdevs which cannot be NULL
and hence no need for NULL check.

Fixes: 2ae84b39ae7b ("eventdev/crypto: store operations in circular buffer")
Signed-off-by: Ganapati Kundapura <ganapati.kundapura@intel.com>
Acked-by: Abhinandan Gujjar <abhinandan.gujjar@intel.com>