Added checking for Volk presence according to @dholm #4 pull request.
diff --git a/lib/CMakeLists.txt b/lib/CMakeLists.txt
index f420820..228897a 100644
--- a/lib/CMakeLists.txt
+++ b/lib/CMakeLists.txt
@@ -42,7 +42,7 @@
)
add_library(gnuradio-gsm SHARED ${gsm_sources})
-target_link_libraries(gnuradio-gsm ${Boost_LIBRARIES} ${GNURADIO_RUNTIME_LIBRARIES}
+target_link_libraries(gnuradio-gsm ${Boost_LIBRARIES} ${GNURADIO_RUNTIME_LIBRARIES} ${VOLK_LIBRARIES}
boost_iostreams
boost_system
boost_filesystem