Revert "ceph-disk-activate: don't override default or configured osd journal path"

This reverts commit 813e9fe2b4291a1c1922ef78f031daa9b78fe53b.

We run --mkfs with the osd disk mounted in a temporary location, so it is
necessary to explicitly pass in these paths.

If we want to support journals in a different location, we need to make
ceph-disk-prepare update the journal symlink accordingly.. not control it via
the config option.

Signed-off-by: Sage Weil <sage@inktank.com>
Revert "ceph-disk-activate: rely on default/configured keyring path"

This reverts commit 936b8f20af1d390976097c427b6e92da4b39b218.

This is necessary because we mount the osd in a temporary location.

Signed-off-by: Sage Weil <sage@inktank.com>