Fix CHGFCNUSG processing when prompted from the WRKFCNUSG screen

If you use option 2 (Change usage) to repeatedly update a Function ID from the Work with Function Usage screen (WRKFCNUSG) the values are not always updated properly.

Assuming that QIBM_QMTF_CLIENT_REQ_0 has DEFAULT(*DENIED) ALLOBJ(*NOTUSED)

1) WRKFCNUSG
2) use option 2 to change QIBM_QTMF_CLIENT_REQ_0:
The CHGFCNUSG command will be prompted and pre-populated with values DEFAULT(*DENIED) ALLOBJ(*NOTUSED)
Update DEFAULT to *ALLOWED then press enter
The values are now correctly set to *ALLOWED and *NOTUSED
3) Use option 2 again, to change QIBM_QTMF_CLIENT_REQ_0:
The CHGFCNUSG command will be prompted and pre-populated with values DEFAULT(*DENIED) ALLOBJ(*NOTUSED)
These values are stale. That's fine, other commands (e.g. WRKAUT) do the same thing.
Don't change anything, just press enter.
A message is displayed saying that QIBM_QTMF_CLIENT_REQ_0 has been updated, presumably to DEFAULT(*DENIED) and ALLOBJ(*NOTUSED) since those were the values displayed when we pressed enter. However, that's not the case. Nothing was actually updated, it's still DEFAULT(*ALLOWED) and ALLOBJ(*NOTUSED).
3) use option 2 again, to change QIBM_QTMF_CLIENT_REQ_0
The CHGFCNUSG command will be prompted and pre-populated with values DEFAULT(*DENIED) ALLOBJ(*NOTUSED)
These values are stale. That's fine, other commands (e.g. WRKAUT) do the same thing.
Leave DEFAULT as *DENIED, but change ALLOBJAUT to *USED and press enter
A message is displayed saying that QIBM_QTMF_CLIENT_REQ_0 has been updated, presumably to DEFAULT(*DENIED) and ALLOBJ(*USED) since those were the values displayed when we pressed enter. However, that's not the case. DEFAULT still wasn't changed to *DENIED, it's still set to *ALLOWED. ALLOBJ was correctly updated to *USED.

The WRKAUT and WRKFCUSG commands function in a similar way in that you need to press refresh for changes to be reflected, but at least when you re-select option 2 from the WRKAUT screen the stale values displayed on the screen are actually used to update the object authorities. That's not the case when re-updating from the WRKFCNUSG screen.