sybaseASE: Run verify_all() for start operation only

The sybaseASE resource agent runs the verify_all() function at the
beginning of start, stop, and monitor operations.

When verify_all() is run for a probe (monitor) operation and
sybase_home resides on a cluster-managed filesystem, the probe often
fails with $OCF_ERR_GENERIC because the filesystem isn't mounted yet.
This prevents the resource from starting on that node.

For the stop operation, there's simply no reason to run verify_all().

This patch removes verify_all() for the stop and monitor operations.
It is now only run for the start operation.

Resolves: RHBZ#1848673
Resolves: RHBZ#1848025