Allow os_tuning_params to overwrite fs.aio-max-nr
Allow os_tuning_params to overwrite fs.aio-max-nr

The order of fs.aio-max-nr (which is hard-coded to 1048576) means that
if you set fs.aio-max-nr in os_tuning_params it will effectively be
ignored for bluestore scenarios.

To resolve this we should move the setting of fs.aio-max-nr above the
setting of os_tuning_params, in this way the operator can define the
value of fs.aio-max-nr to be something other than 1048576 if they want
to.

Additionally, we can make the sysctl settings happen in 1 task rather
than multiple.

(cherry picked from commit 08a2b58d39a687e25436afdf3fda1591d3be8ca1)

fgal/ceph-ansible,fgal/ceph-ansible