Handle of the bag to be cleared. This must be the handle of a bag created
by the user, not the handle of a system bag. MQRC_SYSTEM_BAG_NOT_ALTERABLE
results if you specify the handle of a system bag.
CompCode(MQLONG) - output
Completion code.
Reason(MQLONG) - output
Reason code qualifying CompCode.
The following reason codes indicating error conditions can be returned
from the mqClearBag call: