test/vm_setup.sh: Add sshpass

sshpass used in test/nvme/hotplug.sh test but not present
in vm_setup.sh dependencies.

Change-Id: Ic9d7f137f7694e5318f6f412b1e7a73536a82f8c
Signed-off-by: Karol Latecki <karol.latecki@intel.com>
Reviewed-on: https://review.gerrithub.io/c/438788


Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Darek Stojaczyk <dariusz.stojaczyk@intel.com>
Reviewed-by: Changpeng Liu <changpeng.liu@intel.com>
Chandler-Test-Pool: SPDK Automated Test System <sys_sgsw@intel.com>