clustermd_tests: add test case to test switch-recovery against cluster-raid1

03r1_switch-recovery:
Create new array with 2 active and 1 spare disk, set 1 active disk as 'fail',
it triggers recovery and the spare disk would replace the failure disk, then
stop the array in doing recovery node, the other node would take it over and
continue to complete the recovery.

Signed-off-by: Zhilong Liu <zlliu@suse.com>
Signed-off-by: Jes Sorensen <jsorensen@fb.com>

clustermd_tests/03r1_switch-recovery

@@ -0,0 +1,21 @@
+#!/bin/bash
+
+mdadm -CR $md0 -l1 -b clustered -n2 -x1 $dev0 $dev1 $dev2 --assume-clean
+ssh $NODE2 mdadm -A $md0 $dev0 $dev1 $dev2
+check all nosync
+check all raid1
+check all bitmap
+check all spares 1
+check all state UU
+check all dmesg
+mdadm --manage $md0 --fail $dev0
+sleep 0.3
+check $NODE1 recovery
+stop_md $NODE1 $md0
+check $NODE2 recovery
+check $NODE2 wait
+check $NODE2 state UU
+check all dmesg
+stop_md $NODE2 $md0
+
+exit 0