Initialize RSA context in RSA test suite before first potentially failing operation

The function `rsa_gen_key` from `test_suite_rsa.function` initialized a stack allocated RSA context only after
seeding the CTR DRBG. If the latter operation failed, the cleanup code tried to free the uninitialized RSA context,
potentially resulting in a segmentation fault. Fixes one aspect of #1023.
1 file changed