test/nvmf: Always remove lingering soft rxe devices

In case there are lingering rxe devices present on the system, adding
them again under the infiniband subsystem will simply fail the test.
To avoid such scenario, make sure that we start the rxe with a clean
slate by removing all soft devices first.

This is mostly relevant for systems running jobs which init the rxe
but don't run tests which call to revert_soft_roce() for cleanup (see
BlobFS-autotest as an example).

Change-Id: I12997fbaf7343ae3e9bc0b38f5455f6332c4e6c5
Signed-off-by: Michal Berger <michalx.berger@intel.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/3823
Community-CI: Mellanox Build Bot
Community-CI: Broadcom CI
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Tomasz Zawadzki <tomasz.zawadzki@intel.com>

test/nvmf/common.sh

@@ -43,6 +43,7 @@ function load_ib_rdma_modules() {
 }
 
 function detect_soft_roce_nics() {
+	rxe_cfg stop # make sure we run tests with a clean slate
 	rxe_cfg start
 }