The function call of spdk_nvmf_check_pools can be
directly put in nvmf.c.
Reason: This pool is created by nvmf subsystem,
it should be recycled by this subsystem.
Change-Id: I49e49bcb56079fc25d26b1f5078a1808c2f8e189
Signed-off-by: Ziye Yang <ziye.yang@intel.com>