We don't want to refresh the dfs cache in very short intervals, so
setting a minimum interval of 2 minutes is OK.

If it needs to be refreshed immediately, one could have the cache
cleared with

	$ echo 0 > /proc/fs/cifs/dfscache

and then remounting the dfs share.
Signed-off-by: NPaulo Alcantara (SUSE) <pc@cjr.nz>
Reviewed-by: NAurelien Aptel <aaptel@suse.com>
Signed-off-by: NSteve French <stfrench@microsoft.com>