[GFS2] Reduce number of gfs2_scand processes to one

We only need a single gfs2_scand process rather than the one
per filesystem which we had previously. As a result the parameter
determining the frequency of gfs2_scand runs becomes a module
parameter rather than a mount parameter as it was before.

Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>

fs/gfs2/super.c

@@ -58,7 +58,6 @@ void gfs2_tune_init(struct gfs2_tune *gt)
 	gt->gt_incore_log_blocks = 1024;
 	gt->gt_log_flush_secs = 60;
 	gt->gt_jindex_refresh_secs = 60;
-	gt->gt_scand_secs = 15;
 	gt->gt_recoverd_secs = 60;
 	gt->gt_logd_secs = 1;
 	gt->gt_quotad_secs = 5;