patch 8.2.2855: white space after "->" does not give E274

Problem:    White space after "->" does not give E274.
Solution:   Do not skip white space in legacy script. (closes #8212)
diff --git a/src/testdir/test_method.vim b/src/testdir/test_method.vim
index 262c08c..6b62d36 100644
--- a/src/testdir/test_method.vim
+++ b/src/testdir/test_method.vim
@@ -131,11 +131,12 @@
   eval [1, 2, 3]  
 	\ ->sort(
 	\ )
-  eval [1, 2, 3]-> sort()
+  eval [1, 2, 3]->sort()
 
   call assert_fails('eval [1, 2, 3]->sort ()', 'E274:')
   call assert_fails('eval [1, 2, 3] ->sort ()', 'E274:')
   call assert_fails('eval [1, 2, 3]-> sort ()', 'E274:')
+  call assert_fails('eval [1, 2, 3]-> sort()', 'E274:')
 endfunc
 
 func Test_method_lambda()