OSHMEM: sshmem verbs: improve hca name parsing

If user gives hca port ignore port, use only hca name.
Ex: mlx4_0:1 -> mlx4_0

fixed by @alex-mikheev reviewed by @miked-mellanox
(cherry picked from commit 4ac59362577ef0f48741663281c9caef7f1357a8)
Adding Devendar's solution for OSHMEM's global exit when applications are launched directly with srun.