L3GD20: Ensure init and constructors

src/drivers/l3gd20/l3gd20.cpp

@@ -330,12 +330,18 @@ private:
 	 * @return 0 on success, 1 on failure
 	 */
 	 int 			self_test();
+
+	/* this class does not allow copying */
+	L3GD20(const L3GD20&);
+	L3GD20 operator=(const L3GD20&);
 };
 
 L3GD20::L3GD20(int bus, const char* path, spi_dev_e device, enum Rotation rotation) :
 	SPI("L3GD20", path, bus, device, SPIDEV_MODE3, 11*1000*1000 /* will be rounded to 10.4 MHz, within margins for L3GD20 */),
+	_call{},
 	_call_interval(0),
 	_reports(nullptr),
+	_gyro_scale{},
 	_gyro_range_scale(0.0f),
 	_gyro_range_rad_s(0.0f),
 	_gyro_topic(-1),

src/drivers/l3gd20/module.mk

@@ -6,3 +6,5 @@ MODULE_COMMAND	 = l3gd20
 SRCS		 = l3gd20.cpp
 
 MODULE_STACKSIZE	= 1200
+
+EXTRACXXFLAGS	= -Weffc++