zed: Allow autoreplace and fault LEDs for removed vdevs

Allow zed to autoreplace vdevs marked as REMOVED.  Also update
statechange-led zedlet to toggle fault LEDs for REMOVED vdevs.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Tony Hutter <hutter2@llnl.gov>
Closes #15281

cmd/zed/agents/zfs_mod.c

@@ -372,6 +372,7 @@ zfs_process_add(zpool_handle_t *zhp, nvlist_t *vdev, boolean_t labeled)
 	/* Only autoreplace bad disks */
 	if ((vs->vs_state != VDEV_STATE_DEGRADED) &&
 	    (vs->vs_state != VDEV_STATE_FAULTED) &&
+	    (vs->vs_state != VDEV_STATE_REMOVED) &&
 	    (vs->vs_state != VDEV_STATE_CANT_OPEN)) {
 		zed_log_msg(LOG_INFO, "  not autoreplacing since disk isn't in "
 		    "a bad state (currently %llu)", vs->vs_state);

cmd/zed/zed.d/statechange-led.sh

@@ -121,7 +121,7 @@ state_to_val()
 {
 	state="$1"
 	case "$state" in
-		FAULTED|DEGRADED|UNAVAIL)
+		FAULTED|DEGRADED|UNAVAIL|REMOVED)
 			echo 1
 			;;
 		ONLINE)