Remove double initialisation of AEAD operation
Remove double initialisation of AEAD operation

Signed-off-by: Paul Elliott <c95151bd40fac1aa138ed1651e2873f91d2e1899@arm.com>

NXPmicro/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,NXPmicro/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls