test: avoid repeated screen lines in expected states

This is the command invoked repeatedly to make the changes:

    :%s/^\(.*\)|\%(\*\(\d\+\)\)\?$\n\1|\%(\*\(\d\+\)\)\?$/\=submatch(1)..'|*'..(max([str2nr(submatch(2)),1])+max([str2nr(submatch(3)),1]))/g

test/functional/legacy/matchparen_spec.lua

@@ -47,16 +47,12 @@ describe('matchparen', function()
 
     local screen1 = [[
       {1:^()}                  |
-      {0:~                   }|
-      {0:~                   }|
-      {0:~                   }|
+      {0:~                   }|*3
                           |
     ]]
     local screen2 = [[
       ^aa                  |
-      {0:~                   }|
-      {0:~                   }|
-      {0:~                   }|
+      {0:~                   }|*3
                           |
     ]]