Clean up some ctors/dtors.

devices/common/adb/adb.cpp

@@ -55,8 +55,6 @@ ADB_Bus::ADB_Bus() {
     mouse_access_no    = adb_relative;
 }
 
-ADB_Bus::~ADB_Bus() {}
-
 bool ADB_Bus::listen(int device, int reg) {
     if (device == keyboard_access_no) {
         if (adb_keybd_listen(reg)) {

devices/common/adb/adb.h

@@ -51,7 +51,7 @@ enum adb_default_values {
 class ADB_Bus {
 public:
     ADB_Bus();
-    ~ADB_Bus();
+    ~ADB_Bus() = default;
 
     bool listen(int device, int reg);
     bool talk(int device, int reg, uint16_t value);

devices/common/hwcomponent.h

@@ -45,6 +45,7 @@ enum HWCompType : int {
 /** Abstract base class for HW components. */
 class HWComponent {
 public:
+    HWComponent()          = default;
     virtual ~HWComponent() = default;
 
     virtual std::string get_name(void) {

devices/common/i2c/i2c.h

@@ -47,9 +47,7 @@ public:
     I2CBus() {
         std::memset(this->dev_list, 0, sizeof(this->dev_list));
     };
-    ~I2CBus() {
-        std::memset(this->dev_list, 0, sizeof(this->dev_list));
-    };
+    virtual ~I2CBus() = default;
 
     virtual void register_device(uint8_t dev_addr, I2CDevice* dev_obj) {
         if (this->dev_list[dev_addr]) {

devices/common/mmiodevice.h

@@ -30,6 +30,7 @@ along with this program.  If not, see <https://www.gnu.org/licenses/>.
 /** Abstract class representing a simple, memory-mapped I/O device */
 class MMIODevice : public HWComponent {
 public:
+    MMIODevice()                                                                      = default;
     virtual uint32_t read(uint32_t reg_start, uint32_t offset, int size)              = 0;
     virtual void write(uint32_t reg_start, uint32_t offset, uint32_t value, int size) = 0;
     virtual ~MMIODevice()                                                             = default;