Introduce grub_util_file_sync and use it instead of fsync(fileno(f)).

Fixes build for windows.

grub-core/osdep/aros/hostdisk.c

@@ -485,6 +485,15 @@ grub_util_fd_sync (grub_util_fd_t fd)
     }
 }
 
+void
+grub_util_file_sync (FILE *f)
+{
+  fflush (f);
+  if (!allow_fd_syncs)
+    return;
+  fsync (fileno (f));
+}
+
 void
 grub_util_disable_fd_syncs (void)
 {

grub-core/osdep/unix/hostdisk.c

@@ -200,6 +200,15 @@ grub_util_fd_sync (grub_util_fd_t fd)
     fsync (fd);
 }
 
+void
+grub_util_file_sync (FILE *f)
+{
+  fflush (f);
+  if (!allow_fd_syncs)
+    return;
+  fsync (fileno (f));
+}
+
 void
 grub_util_disable_fd_syncs (void)
 {

grub-core/osdep/windows/hostdisk.c

@@ -584,12 +584,16 @@ grub_util_fopen (const char *path, const char *mode)
   return ret;
 }
 
-int fsync (int fno)
+void
+grub_util_file_sync (FILE *f)
 {
   HANDLE hnd;
-  hnd = (HANDLE) _get_osfhandle (fno);
+
+  fflush (f);
+  if (!allow_fd_syncs)
+    return;
+  hnd = (HANDLE) _get_osfhandle (fileno (f));
   FlushFileBuffers (hnd);
-  return 0;
 }
 
 int