storage/nfs: fix deadlock when connecting

The Connect method can be called between Schedule and lock. In that case, when
locked, the state is already set to CONNECTING of READY and the condition won't
be signaled anymore.

src/storage/plugins/NfsStorage.cxx

@@ -177,6 +177,8 @@ private:
 				mutex.unlock();
 				DeferredMonitor::Schedule();
 				mutex.lock();
+				if (state == State::INITIAL)
+					cond.wait(mutex);
 				break;
 
 			case State::CONNECTING:
@@ -188,8 +190,6 @@ private:
 				error.Set(last_error);
 				return false;
 			}
-
-			cond.wait(mutex);
 		}
 	}