UI/cleanup: Remove most redraw_later_clear() calls

Vim :! may "mess up the screen" because of e.g. switching between cooked
mode, but Nvim just uses pipes. So maybe we can avoid these
redraw_later_clear() CYA calls.

src/nvim/os_unix.c

@@ -419,7 +419,6 @@ int mch_expand_wildcards(int num_pat, char_u **pat, int *num_file,
     xfree(tempname);
     // With interactive completion, the error message is not printed.
     if (!(flags & EW_SILENT)) {
-      redraw_later_clear();             // probably messed up screen
       msg_putchar('\n');                // clear bottom line quickly
 #if SIZEOF_LONG > SIZEOF_INT
       assert(Rows <= (long)INT_MAX + 1);