patch 9.0.1330: handling new value of an option has a long "else if" chain

Problem:    Handling new value of an option has a long "else if" chain.
Solution:   Use a function pointer. (Yegappan Lakshmanan, closes #12015)
diff --git a/src/proto/ex_getln.pro b/src/proto/ex_getln.pro
index 88f0175..956916d 100644
--- a/src/proto/ex_getln.pro
+++ b/src/proto/ex_getln.pro
@@ -39,7 +39,7 @@
 void f_setcmdpos(typval_T *argvars, typval_T *rettv);
 int get_cmdline_firstc(void);
 int get_list_range(char_u **str, int *num1, int *num2);
-char *check_cedit(void);
+char *did_set_cedit(optset_T *args);
 int is_in_cmdwin(void);
 char_u *script_get(exarg_T *eap, char_u *cmd);
 void get_user_input(typval_T *argvars, typval_T *rettv, int inputdialog, int secret);