darwin: Correct interpretation of COM-style Release() return value

Found thanks to a warning about implicit sign conversion.

The return value is the new reference count, not an IOReturn error code.

I'm not sure if this is copy paste, and the new ref count is
unimportant, so I just preserved the existing behaviour (but adjusted
the log message). The change only impacts debug logs anyway.

References #1414

libusb/os/darwin_usb.c

diff --git a/libusb/os/darwin_usb.c b/libusb/os/darwin_usb.c
index 98d96dc..106ec87 100644
--- a/libusb/os/darwin_usb.c
+++ b/libusb/os/darwin_usb.c
@@ -1868,9 +1868,10 @@
   if (kresult != kIOReturnSuccess)
     usbi_warn (HANDLE_CTX (dev_handle), "USBInterfaceClose: %s", darwin_error_str(kresult));
 
-  kresult = (*IOINTERFACE(cInterface))->Release(IOINTERFACE(cInterface));
-  if (kresult != kIOReturnSuccess)
-    usbi_warn (HANDLE_CTX (dev_handle), "Release: %s", darwin_error_str(kresult));
+  ULONG refCount = (*IOINTERFACE(cInterface))->Release(IOINTERFACE(cInterface));
+  if (refCount != 0) {
+    usbi_warn (HANDLE_CTX (dev_handle), "Release final refCount: %u", refCount);
+  }
 
   IOINTERFACE(cInterface) = NULL;
 

libusb/version_nano.h

diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index 8f1b9f0..677ea88 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11889
+#define LIBUSB_NANO 11890