Handle GPFS EUNTACH errors.

Need to exit when GPFS returns
EUNTACH to avoid error going back to client.

Signed-off-by: Rong Zeng <rongzeng@us.ibm.com>
Merge branch 'tp/ptfixes' into ibm_next_20_tmp
Merge branch 'tp/up-ops' into ibm_next_20_tmp
Merge branch 'tp/handle_eunatch' into ibm_next_20_tmp