Removes unused variables in test_suite_rsa.function
Removes unused variables in test_suite_rsa.function

CI was failing on check_params due to
MBEDTLS_RSA_PRIVATE being assigned to a now
superfluous variable. The variable has been
as well as another superfluous variable.
This should correct the CI issue.

Signed-off-by: Thomas Daubney <5b910c8e7c225fd62319de5b44eecef1f6356fe1@arm.com>

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