Added check for the return value of the RAND_bytes() function

Added check for the return value of the RAND_bytes() function

Call app_bail_out if RAND_bytes() fails.

Also changed the output parameter of RAND_bytes() to inp as
writing to encrypted output buffer does not make sense.

Reviewed-by: Matt Caswell <matt@openssl.org>
Reviewed-by: Tom Cosgrove <tom.cosgrove@arm.com>
Reviewed-by: Paul Dale <pauli@openssl.org>
Reviewed-by: Tomas Mraz <tomas@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/21706)