[GFS2] make lock_dlm drop_count tunable in sysfs

We want to be able to change or disable the default drop_count (number at
which the dlm asks gfs to limit the the number of locks it's holding).
Add it to the collection of sysfs tunables for an fs.

Signed-off-by: David Teigland <teigland@redhat.com>
Signed-off-by: Steven Whitehouse <swhiteho@redhat.com>
diff --git a/fs/gfs2/locking/dlm/mount.c b/fs/gfs2/locking/dlm/mount.c
index cdd1694..1d8faa3 100644
--- a/fs/gfs2/locking/dlm/mount.c
+++ b/fs/gfs2/locking/dlm/mount.c
@@ -9,8 +9,6 @@
 
 #include "lock_dlm.h"
 
-int gdlm_drop_count;
-int gdlm_drop_period;
 const struct lm_lockops gdlm_ops;
 
 
@@ -24,8 +22,8 @@
 	if (!ls)
 		return NULL;
 
-	ls->drop_locks_count = gdlm_drop_count;
-	ls->drop_locks_period = gdlm_drop_period;
+	ls->drop_locks_count = GDLM_DROP_COUNT;
+	ls->drop_locks_period = GDLM_DROP_PERIOD;
 	ls->fscb = cb;
 	ls->sdp = sdp;
 	ls->fsflags = flags;