Use WEBOS_DISTRO_PRERELEASE in production builds

:Release Notes:
Apply to disable some check function for logs.

:Detailed Notes:
If the WEBOS_DISTRO_PRERELEASE is defined when compile time,
every log shouldn't be checked whether it's format is right
in runtime.

:Testing Performed:
Compiled locally and tested on emulator and devices.
Verified in the log file, error text displayed in
/var/log/messages properly.

:QA Notes:

:Issues Addressed:
[GF-7721] pmloglib: Use WEBOS_DISTRO_PRERELEASE to disable ...

Open-webOS-DCO-1.0-Signed-off-by: Hongjeon Ha <hj.ha@lge.com>

Change-Id: I14329a6c9b5d1a614e7626a07b740e31e00e724f
Reviewed-on: https://g2g.palm.com/3443
Reviewed-by: Hongjeon Ha <hj.ha@lge.com>
Tested-by: Hongjeon Ha <hj.ha@lge.com>
Reviewed-by: Keith Derrick <keith.derrick@lge.com>