fixed the comment of Opts.DeadlockTimeout in deadlock.go (#23)

deadlock.go

@@ -21,7 +21,7 @@ var Opts = struct {
  // Would disable lock order based deadlock detection if DisableLockOrderDetection == true.
  DisableLockOrderDetection bool
  // Waiting for a lock for longer than DeadlockTimeout is considered a deadlock.
- // Ignored is DeadlockTimeout <= 0.
+ // Ignored if DeadlockTimeout <= 0.
  DeadlockTimeout time.Duration
  // OnPotentialDeadlock is called each time a potential deadlock is detected -- either based on
  // lock order or on lock wait time.