Fix various USB warnings

Fix the following warnings:
-[Warning] USBTester.cpp@45,0:  #1299-D: members and base-classes will
    be initialized in declaration order, not in member initialisation
    list order
-[Warning] USBTester.h@41,0:  #1300-D: ~USBTester inherits implicit
    virtual
-[Warning] USBAudio.cpp@345,0:  #1035-D: single-precision operand
    implicitly converted to double-precision
-[Warning] USBHID.cpp@29,0:  #1300-D: ~AsyncSend inherits implicit
    virtual
-[Warning] USBHID.cpp@61,0:  #1300-D: ~AsyncRead inherits implicit
    virtual
-[Warning] USBHID.cpp@93,0:  #1300-D: ~AsyncWait inherits implicit
    virtual
-[Warning] EndpointResolver.cpp@125,26: '<<' in boolean context, did
    you mean '<' ? [-Wint-in-bool-context]

TESTS/usb_device/basic/USBTester.cpp

@@ -41,8 +41,9 @@
 
 
 USBTester::USBTester(USBPhy *phy, uint16_t vendor_id, uint16_t product_id, uint16_t product_release):
-                        USBDevice(phy, vendor_id, product_id, product_release), reset_count(0), suspend_count(0),
-                        resume_count(0), interface_0_alt_set(NONE), interface_1_alt_set(NONE), configuration_set(NONE)
+                        USBDevice(phy, vendor_id, product_id, product_release), interface_0_alt_set(NONE),
+                        interface_1_alt_set(NONE), configuration_set(NONE), reset_count(0),
+                        suspend_count(0), resume_count(0)
 {
 
     EndpointResolver resolver(endpoint_table());

TESTS/usb_device/basic/USBTester.h

@@ -38,7 +38,7 @@ public:
     */
     USBTester(USBPhy *phy, uint16_t vendor_id, uint16_t product_id, uint16_t product_release);
 
-    ~USBTester();
+    virtual ~USBTester();
 
     /*
     *

usb/device/USBAudio/USBAudio.cpp

@@ -342,7 +342,7 @@ float USBAudio::get_volume()
 {
     lock();
 
-    float ret = _mute ? 0.0 : _volume;
+    float ret = _mute ? 0.0f : _volume;
 
     unlock();
     return ret;

usb/device/USBDevice/EndpointResolver.cpp

@@ -122,7 +122,7 @@ int EndpointResolver::next_index(usb_ep_type_t type, bool in_not_out)
             continue;
         }
 
-        if (shared && (1 << other)) {
+        if (shared && (_used & (1 << other))) {
             // This endpoint can only be one direction at a time and is in
             // use by the other direction
             continue;

usb/device/USBHID/USBHID.cpp

@@ -26,7 +26,7 @@ public:
 
     }
 
-    ~AsyncSend()
+    virtual ~AsyncSend()
     {
 
     }
@@ -58,7 +58,7 @@ public:
 
     }
 
-    ~AsyncRead()
+    virtual ~AsyncRead()
     {
 
     }
@@ -90,7 +90,7 @@ public:
 
     }
 
-    ~AsyncWait()
+    virtual ~AsyncWait()
     {
 
     }