Fix bug in generate_code.pl
Fix bug in generate_code.pl

The following did fail:

Test 1
foo:SOME_CONSTANT:"string"

Test 2
foo:OTHER_CONSTANT:"string"

due to the first string actually including the second "foo" up to (but no
including) the colon.

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