After passing some inputs, try getting one byte of output, just to
check that this succeeds (for a valid sequence of inputs) or fails
with BAD_STATE (for an invalid sequence of inputs). Either output a
1-byte key or a 1-byte buffer depending on the test data.
The test data was expanded as follows:
* Output key type (or not a key): same as the SECRET input if success
is expected, otherwise NONE.
* Expected status: PSA_SUCCESS after valid inputs, BAD_STATE after any
invalid input.