Delay: wait a bit more testing the module

In some environments the time ranges checked are too strict causing test to
fail.
Previously the maximum error accepted was 10 ms, increase to 50 ms.
Also increase timeouts to reduce error/value ratio.

Signed-off-by: Frediano Ziglio <frediano.ziglio@cloud.com>

Author: freddy77

ocaml/libs/xapi-stdext/lib/xapi-stdext-threads/threadext_test.ml

@@ -31,15 +31,15 @@ Single simple signal stored
 let simple () =
   let d = Delay.make () in
   Delay.signal d ;
-  delay_wait_check ~min:0. ~max:0.01 d 1.0 false
+  delay_wait_check ~min:0. ~max:0.05 d 1.0 false
 
 (*
 No signal
 - wait on same thread should timeout more or less on delay
 *)
 let no_signal () =
   let d = Delay.make () in
-  delay_wait_check ~min:0.1 ~max:0.11 d 0.1 true
+  delay_wait_check ~min:0.2 ~max:0.25 d 0.2 true
 
 (*
 Signal twice, collapsed
@@ -52,8 +52,8 @@ let collapsed () =
   let d = Delay.make () in
   Delay.signal d ;
   Delay.signal d ;
-  delay_wait_check ~min:0. ~max:0.01 d 0.1 false ;
-  delay_wait_check ~min:0.1 ~max:0.11 d 0.1 true
+  delay_wait_check ~min:0. ~max:0.05 d 0.2 false ;
+  delay_wait_check ~min:0.2 ~max:0.25 d 0.2 true
 
 (*
 Signal from another thread
@@ -62,8 +62,8 @@ Signal from another thread
 *)
 let other_thread () =
   let d = Delay.make () in
-  let th = Thread.create (fun d -> Thread.delay 0.1 ; Delay.signal d) d in
-  delay_wait_check ~min:0.1 ~max:0.11 d 1.0 false ;
+  let th = Thread.create (fun d -> Thread.delay 0.2 ; Delay.signal d) d in
+  delay_wait_check ~min:0.2 ~max:0.25 d 1.0 false ;
   Thread.join th
 
 let tests =