Change warnings to error in case the iridium driver start failed

ROMFS/px4fmu_common/init.d/rc.mavlink

@@ -164,7 +164,6 @@ then
 	then
 		mavlink start -d /dev/iridium -m iridium -b 115200
 	else
-		echo "WARN: Iridiumsbd driver not started, reboot"
 		tune_control play -m "ML<<CP4CP4CP4CP4CP4"
 	fi
 fi

src/drivers/telemetry/iridiumsbd/IridiumSBD.cpp

@@ -251,7 +251,7 @@ void IridiumSBD::main_loop(int argc, char *argv[])
 	}
 
 	if (arg_uart_name == 0) {
-		PX4_WARN("no Iridium SBD modem UART port provided!");
+		PX4_ERR("no Iridium SBD modem UART port provided!");
 		_task_should_exit = true;
 		return;
 	}
@@ -269,7 +269,7 @@ void IridiumSBD::main_loop(int argc, char *argv[])
 	}
 
 	if (!command_executed) {
-		PX4_WARN("failed to open UART port!");
+		PX4_ERR("failed to open UART port!");
 		_task_should_exit = true;
 		return;
 	}
@@ -289,7 +289,7 @@ void IridiumSBD::main_loop(int argc, char *argv[])
 	}
 
 	if (!command_executed) {
-		PX4_WARN("modem not responding");
+		PX4_ERR("modem not responding");
 		_task_should_exit = true;
 		return;
 	}
@@ -309,7 +309,7 @@ void IridiumSBD::main_loop(int argc, char *argv[])
 	}
 
 	if (!command_executed) {
-		PX4_WARN("modem not responding");
+		PX4_ERR("modem not responding");
 		_task_should_exit = true;
 		return;
 	}