coverity#982973: Resource leak

Change-Id: I1ea51b29c3ad05016f42c215b71877cd8c3f92f4
Reviewed-on: https://gerrit.libreoffice.org/3821Reviewed-by: Noel Power <noel.power@suse.com>
Tested-by: Noel Power <noel.power@suse.com>

extensions/source/nsplugin/source/so_env.cxx

@@ -132,6 +132,7 @@ int nspluginOOoModuleHook (void** aResult)
         fprintf (stderr, "Can't open myself '%s'\n", dlerror());
         return 1;
     }
+    dlclose(dl_handle);
 
     Dl_info dl_info = { 0,0,0,0 };
     if(!dladdr((void *)nspluginOOoModuleHook, &dl_info))