linker: cleanup (removing unused VNDK_VER)

VNDK_VER runtime variable in the linker config file is not used any
more.

Test: m
Change-Id: Id08add6d0259a420ff4819f33093ce388bb3cbe9
diff --git a/linker/linker_config.cpp b/linker/linker_config.cpp
index 46c91a3..a8c0e36 100644
--- a/linker/linker_config.cpp
+++ b/linker/linker_config.cpp
@@ -408,9 +408,6 @@
       params.push_back({ "SDK_VER", buf });
     }
 
-    static std::string vndk = Config::get_vndk_version_string('-');
-    params.push_back({ "VNDK_VER", vndk });
-
     for (auto& path : paths) {
       format_string(&path, params);
     }