ceph: do not force go path in unit tests
ceph: do not force go path in unit tests

Do not force unit tests to be run while the rook repo is in the GOPATH.
Now that Rook uses go modules, this is no longer necessary. Allow this
by creating a helper function that unit tests can use that return the
on-host path to the `rook` project root.

Followup of https://github.com/rook/rook/pull/7119/commits/15a487cd5aa5d4dc59bc15ef610cb182257d9287

Signed-off-by: Sébastien Han <62d754cc350e84d3b1c32ae79f976f5348e74a40@redhat.com>

rook/nfs,rook/rook,rook/rook,rook/nfs,rook/rook,rook/rook,rook/nfs,rook/rook