Remove barely-used redirect functions
Remove barely-used redirect functions

redirect_out was no longer used and redirect_err was only used to
quiet dd. Change the dd invocation to only print diagnostics on
error (on platforms where this is possible).

Signed-off-by: Gilles Peskine <f805f64266d288fc5467baa7be6cd0ff366f477b@arm.com>

NXPmicro/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,Mbed-TLS/mbedtls,NXPmicro/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,ARMmbed/mbedtls,Mbed-TLS/mbedtls