Add the correct sources for libvorbisfile.

libs/libvorbis-1.3.3/CMakeLists.txt

@@ -50,13 +50,13 @@ if(VORBIS_BUILD_SHARED)
 endif()
 
 if(VORBISFILE_BUILD_STATIC)
-	add_library(vorbisfile-static STATIC ${VORBIS_SRC})
+	add_library(vorbisfile-static STATIC ${VORBISFILE_SRC})
 	target_include_directories(vorbisfile-static PUBLIC include)
 	target_link_libraries(vorbisfile-static vorbis-static ${OGG_LIBRARY})
 endif()
 
 if(VORBISFILE_BUILD_SHARED)
-	add_library(vorbisfile SHARED ${VORBIS_SRC} win32/vorbis.def)
+	add_library(vorbisfile SHARED ${VORBISFILE_SRC} win32/vorbis.def)
 	target_include_directories(vorbisfile PUBLIC include)
 	target_link_libraries(vorbisfile vorbis ${OGG_LIBRARY})
 endif()