test: process: Connect signal before launching process

The procFinished event handler is registered after the process is
started. This doesn't actually create any race, as the finished signal
is emitted after a SIGCHLD is caught and handled through the
ProcessManager and processed by the event loop.

However, to follow the best practice that resources should be acquired
before performing an action, connect the finished signal before starting
the process.

Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>

test/process/process_test.cpp

@@ -47,12 +47,13 @@ protected:
 		int exitCode = 42;
 		vector<std::string> args;
 		args.push_back(to_string(exitCode));
+		proc_.finished.connect(this, &ProcessTest::procFinished);
+
 		int ret = proc_.start("/proc/self/exe", args);
 		if (ret) {
 			cerr << "failed to start process" << endl;
 			return TestFail;
 		}
-		proc_.finished.connect(this, &ProcessTest::procFinished);
 
 		timeout.start(100);
 		while (timeout.isRunning())