stm32mp: stm32prog: fix OTP read/write error management

Avoid to ignore the OTP read/write error and transmits the error
to STM32CubeProgrammer.

Today the error is only displayed in log error:
so the user on HOST thinks the OTP operation is performed.

Reported-by: Mickael GARDET <m.gardet@overkiz.com>
Signed-off-by: Patrick Delaunay <patrick.delaunay@foss.st.com>
Fixes: 75ea9e75931c ("stm32mp: stm32prog: add TEE support in stm32prog command")
Reviewed-by: Patrice Chotard <patrice.chotard@foss.st.com>