fix(mbedtls): fix error return code for calc_hash

Make this function return values from crypto_ret_value.
The previous method of returning the mbedtls error code
on failure meant that the authentication module couldn't
correctly parse failures from this function.

Change-Id: I9fe6eba1fc79e8f81004f8cd202781aea907e963
Signed-off-by: Ryan Everett <ryan.everett@arm.com>
1 file changed