Hooks: hook-usb: Resolve library name reported by usb.backend.

hook-usb.py "asks" pyusb which library to pack by inspecting
usb.backend. This only results in a library name (e.g libusb-1.0.so.0),
which is sufficient for ctypes to load the library, but not enough for
pyinstaller to find the file and pack it. This commit solves this problem
by using _resolveCtypesImports to figure out the full path to the file
pyusb loads.

Fixes #2633

PyInstaller/hooks/hook-usb.py

@@ -40,7 +40,9 @@
     binaries = []
     for usblib in [getattr(usb.backend, be)._lib for be in backends]:
         if usblib is not None:
-            binaries = [(usblib._name, '')]
+            binaries = _resolveCtypesImports([os.path.basename(usblib._name)])
+            assert len(binaries[0]) == 3
+            binaries = [(binaries[0][1], '')]
 
 except (ValueError, usb.core.USBError) as exc:
     logger.warning("%s", exc)