Fix memory leak in process_value().

systemverilog-plugin/UhdmAst.cc

diff --git a/systemverilog-plugin/UhdmAst.cc b/systemverilog-plugin/UhdmAst.cc
index 1a2635d..06b4f84 100644
--- a/systemverilog-plugin/UhdmAst.cc
+++ b/systemverilog-plugin/UhdmAst.cc
@@ -1535,6 +1535,7 @@
         if (is_signed) {
             strValType += "s";
         }
+        vpi_release_handle(typespec_h);
     }
     if (val.format) { // Needed to handle parameter nodes without typespecs and constants
         switch (val.format) {