LU-12759 osc: don't re-enable grant shrink on reconnect

LU-12759 osc: don't re-enable grant shrink on reconnect

client requests grant shrinking support on each
reconnect and re-enables the capability even it was
explicitly disabled by lctl set_param.

Lustre-change: https://review.whamcloud.com/36177
Lustre-commit: efa3425c5f5a6763ea834408b982e4df5a90c914

Cray-bug-id: LUS-7585
Signed-off-by: Alexander Zarochentsev <c17826@cray.com>
Change-Id: I87b1718022ee3346c9b177890a118410c5757458
Reviewed-by: Andrew Perepechko <c17827@cray.com>
Reviewed-by: Andriy Skulysh <c17819@cray.com>
Signed-off-by: Minh Diep <mdiep@whamcloud.com>
Reviewed-on: https://review.whamcloud.com/37152
Tested-by: jenkins <devops@whamcloud.com>
Reviewed-by: Andreas Dilger <adilger@whamcloud.com>
Tested-by: Maloo <maloo@whamcloud.com>