oxenstored: fix del_watches and del_transactions

The statement to reset nb_watches should be in del_watches, not
del_transactions.

Signed-off-by: Wei Liu <wei.liu2@citrix.com>
Cc: David Scott <dave.scott@citrix.com>
Acked-by: David Scott <dave.scott@citrix.com>
[ ijc -- fix syntax error by adding a ";" to the previous line in the
         new location and removing from the previous line in the old ]

tools/ocaml/xenstored/connection.ml

@@ -187,11 +187,11 @@ let del_watch con path token =
 	apath, w
 
 let del_watches con =
-  Hashtbl.clear con.watches
+  Hashtbl.clear con.watches;
+  con.nb_watches <- 0
 
 let del_transactions con =
-  Hashtbl.clear con.transactions;
-  con.nb_watches <- 0
+  Hashtbl.clear con.transactions
 
 let list_watches con =
 	let ll = Hashtbl.fold