vim-patch:8.1.2058: function for ex command is named inconsistently

Problem:    Function for ex command is named inconsistently.
Solution:   Rename do_marks() to ex_marks().
4bd782339e

src/nvim/ex_cmds.lua

@@ -1632,7 +1632,7 @@ return {
     command='marks',
     flags=bit.bor(EXTRA, TRLBAR, CMDWIN),
     addr_type=ADDR_LINES,
-    func='do_marks',
+    func='ex_marks',
   },
   {
     command='match',