Returning (exiting with) negative exit codes isn't user friendly,
because the user must output the exit code with the shell, convert it
from its unsigned 8-bit value back to the negative value, and then
look up where that comes from in the code (which may be multiple
places). Use the kselftests TAP interface, instead.
Signed-off-by: Andrew Jones <ajones@ventanamicro.com>
Link: https://lore.kernel.org/r/20230918131518.56803-13-ajones@ventanamicro.comSigned-off-by: Palmer Dabbelt <palmer@rivosinc.com>