LU-17789 pcc: dont auto PCCRO attach for write/setattr

LU-17789 pcc: dont auto PCCRO attach for write/setattr

It is meaningless for a client to do auto PCCRO attach for write
and setattr operations.
Moreover, it may result in sanity-pcc/test_21d failure as
follows:
"FAIL: expected /mnt/lustre/f21d.sanity-pcc: write_mod_data,
got: write_mod_dataa"

This patch fixed it by disabling PCCRO auto attach for write and
setattr operations.

Change-Id: I894db1953a119d12e9337251c069c594fb40482a
Test-Parameters: testlist=sanity-pcc env=ONLY=21d,ONLY_REPEAT=10
Signed-off-by: Qian Yingjin <qian@ddn.com>
Reviewed-on: https://review.whamcloud.com/c/ex/lustre-release/+/54946
Tested-by: jenkins <devops@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>