Explicitly specify exit code for "exit /b"
Explicitly specify exit code for "exit /b"

"exit /b" without an explicit exit value doesn't copy the value of the
last command executed, causing issues on Jenkins.

Signed-off-by: Bence Szépkúti <f5a052dc170d15117fd347c2abf2400eb6ae5243@arm.com>

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