fix(scp remote_files): do not filter generated paths with "$cur"

This is a regression introduced by commit f2df91d, where
`_comp_split` was replaced by `_comp_compgen_split` assuming that the
generated words are starting with "$cur".  However, we here would like
to generate the paths essentially starting with `_path=${cur#*:}`
instead of $cur because the caller re-assembles $cur with `-n :`, yet
Readline expects the words after `:`.

Fixes #1157

completions/ssh

@@ -499,7 +499,7 @@ _comp_xfunc_scp_compgen_remote_files()
             command sed -e 's/'"$_comp_cmd_scp__path_esc"'/\\\\\\&/g' -e 's/[*@|=]$//g' \
                 -e 's/[^\/]$/& /g')
     fi
-    _comp_compgen_split -l -- "$_files"
+    _comp_compgen -R split -l -- "$_files"
 }
 
 # @deprecated 2.12 use `_comp_compgen -ax ssh remote_files` instead