fixing command according to description and results (#417) (#421)

Cherry-picked from #417

Author: lidiazuin

modules/ROOT/pages/access-control/manage-roles.adoc

@@ -491,7 +491,7 @@ The roles assigned to each user can be seen in the list provided by `SHOW USERS`
 
 [source, cypher, role=noplay]
 ----
-SHOW ROLES
+SHOW USERS
 ----
 
 .Result
@@ -545,7 +545,7 @@ GRANT ROLES role1, role2 TO user1, user2, user3
 
 [source, cypher, role=noplay]
 ----
-SHOW ROLES
+SHOW USERS
 ----
 
 .Result
@@ -605,7 +605,7 @@ The roles revoked from users can no longer be seen in the list provided by `SHOW
 
 [source, cypher, role=noplay]
 ----
-SHOW ROLES
+SHOW USERS
 ----
 
 .Result