Changes

vty: Fix 'update route' parameter comment descriptions

There was one string which was not mapping to any actual param, making
subsequent param descriptions show up incorrectly during VTY operation.

Related: SYS#7112
(cherry picked from commit bfd6d20376c5ea0d1f9e87ca32a9ff5c6fe99c98)
Change-Id: I9b48fe9072f613c18c82965ef5aabd239b576a07