Move the merge_action_e enum to the Win32 file dialog source file.

It's only used with the Windows dialog, so no need to make it public.

Change-Id: I4976748d642399b57abc89bccc26f680e3938509
Reviewed-on: https://code.wireshark.org/review/25719
Reviewed-by: Guy Harris <guy@alum.mit.edu>

ui/file_dialog.h

@@ -21,12 +21,6 @@ typedef enum {
   CANCELLED
 } check_savability_t;
 
-typedef enum {
-    merge_append,
-    merge_chrono,
-    merge_prepend
-} merge_action_e;
-
 typedef enum {
     export_type_text = 1,
     export_type_ps,

ui/win32/file_dlg_win32.c

@@ -41,6 +41,12 @@
 
 #include "file_dlg_win32.h"
 
+typedef enum {
+    merge_append,
+    merge_chrono,
+    merge_prepend
+} merge_action_e;
+
 #define FILE_OPEN_DEFAULT 1 /* All Files */
 
 #define FILE_MERGE_DEFAULT FILE_OPEN_DEFAULT