Describe the bug
Latest OS_open() does not support O_RDONLY flag

To Reproduce
Just observation trying to find other bug - no solution for that one yet...

Expected behavior
Correct #define use

Code snips
If applicable, add references to the software.

System observed on:

• Docker
• OS: Linux fb2def16b3c1 4.19.104-microsoft-standard Documentation is being improperly recognized as code on GitHub #1 SMP Wed Feb 19 06:37:35 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux
• Versions [Versions:cFE 6.7.20.0, OSAL 5.0.20.0, PSP 1.4.14.0]

Additional context
Add any other context about the problem here.

Reporter Info
Maurice Smulders / Geneva Technologies inc