os/bluestore: print error log if get_return_value return error

Signed-off-by: mychoxin <mychoxin@gmail.com>

src/os/bluestore/KernelDevice.cc

@@ -362,11 +362,17 @@ void KernelDevice::_aio_thread()
 	io_since_flush.store(true);
 
 	int r = aio[i]->get_return_value();
+	if (r < 0) {
+	  derr << __func__ << " finished aio " << aio[i] << " r " << r
+	       << " ioc " << ioc
+	       << " with " << (ioc->num_running.load() - 1)
+	       << " aios left" << dendl;
+	  assert(r >= 0);
+	}
 	dout(10) << __func__ << " finished aio " << aio[i] << " r " << r
 		 << " ioc " << ioc
 		 << " with " << (ioc->num_running.load() - 1)
 		 << " aios left" << dendl;
-	assert(r >= 0);
 
 	// NOTE: once num_running and we either call the callback or
 	// call aio_wake we cannot touch ioc or aio[] as the caller