Fixes error checking the slice instance status in 'Check For Network Slice Instance For Failure' keyword.

Change-Id: Ibfac29493be66a52f12f8e3874c3f1fa83e9bba9
Signed-off-by: aguilarherna <daguilarh@indra.es>
diff --git a/robot-systest/lib/nsi_lib.robot b/robot-systest/lib/nsi_lib.robot
index abbba52..2169f7f 100644
--- a/robot-systest/lib/nsi_lib.robot
+++ b/robot-systest/lib/nsi_lib.robot
@@ -172,7 +172,7 @@
     ${rc}   ${stdout}=   Run and Return RC and Output   osm nsi-list --filter name="${slice_name}"
     log   ${stdout}
     Should Be Equal As Integers   ${rc}   ${success_return_code}
-    Should Not Contain   ${stdout}   BROKEN
+    Should Not Contain   ${stdout}   failed
 
 
 Delete NSI