Add missing dealloc (#3061)

Fixes #3060
diff --git a/test/fuzzers/spvtools_as_fuzzer.cpp b/test/fuzzers/spvtools_as_fuzzer.cpp
index 92aa47f..8cecb05 100644
--- a/test/fuzzers/spvtools_as_fuzzer.cpp
+++ b/test/fuzzers/spvtools_as_fuzzer.cpp
@@ -66,5 +66,7 @@
     binary = nullptr;
   }
 
+  spvContextDestroy(context);
+
   return 0;
 }