Merge pull request 'Use library paths from pkg-config' (#4) from argi…

…lo/rtl-sdr:libusb-pkgconfig into master

Reviewed-on: https://gitea.osmocom.org/sdr/rtl-sdr/pulls/4

CMakeLists.txt

@@ -71,6 +71,7 @@ find_package(PkgConfig)
 
 if(PKG_CONFIG_FOUND)
     pkg_check_modules(LIBUSB libusb-1.0 IMPORTED_TARGET)
+    set(LIBUSB_LIBRARIES "${LIBUSB_LINK_LIBRARIES}")
 else()
     set(LIBUSB_LIBRARIES "" CACHE STRING "manual libusb path")
     set(LIBUSB_INCLUDE_DIRS "" CACHE STRING "manual libusb includepath")