Move rootNode member initialization from cpp to header.

Author: forderud

libraries/HID/src/HID.cpp

@@ -146,8 +146,7 @@ bool HID_::setup(USBSetup& setup)
 	return false;
 }
 
-HID_::HID_(void) : PluggableUSBModule(1, 1, epType),
-                   rootNode(NULL)
+HID_::HID_(void) : PluggableUSBModule(1, 1, epType)
 {
 	epType[0] = EP_TYPE_INTERRUPT_IN;
 	PluggableUSB().plug(this);

libraries/HID/src/HID.h

@@ -106,7 +106,7 @@ class HID_ : public PluggableUSBModule
 private:
   uint8_t epType[1];
 
-  HIDSubDescriptor* rootNode;
+  HIDSubDescriptor* rootNode = NULL;
   uint16_t descriptorSize = 0;
 
   uint8_t protocol = HID_REPORT_PROTOCOL;