usrp: Applied patch from Michael Dickens for Darwin libusb

Update usrp_libusb.m4 to work on Darwin for both libusb-legacy and libusb1

diff --git a/config/usrp_libusb.m4 b/config/usrp_libusb.m4
index 6ed7f5e9fc5bf24a096ba400fa113046e87e0faf..428a57992325e56c40af598f1191377084a29876 100755 (executable)
--- a/config/usrp_libusb.m4
+++ b/config/usrp_libusb.m4
@@ -91,14 +91,18 @@ AC_DEFUN([USRP_LIBUSB], [
       AC_LANG_PUSH(C)
       save_LIBS="$LIBS"
       LIBS=""
+      case "$host_os" in
+        darwin*)
+          USB_LIBS="$USB_LIBS -lIOKit"
+          LIBS="$USB_LIBS"
+          ;;
+        *) ;;
+      esac
       AC_CHECK_LIB([$usb_lib_name], [$usb_lib_func], [], [
         libusbok=no
         AC_MSG_RESULT([USRP requires library '$usb_lib_name' with function '$usb_lib_func', which was either not found or was not usable. See http://www.libusb.org])
       ])
       case "$host_os" in
-        darwin*)
-          USB_LIBS="$USB_LIBS -lIOKit"
-          ;;
         cygwin* | mingw*)
           USB_LIBS="$LIBS"
           ;;