Fix resource leak (node)

Scanner Output
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Error: RESOURCE_LEAK (CWE-772): [#def1]
libtasn1-4.16.0/lib/coding.c:1099: alloc_fn: Storage is returned from allocation function "_asn1_copy_structure3".
libtasn1-4.16.0/lib/coding.c:1099: var_assign: Assigning: "node" = storage returned from "_asn1_copy_structure3(node)".
libtasn1-4.16.0/lib/coding.c:1106: leaked_storage: Variable "node" going out of scope leaks the storage it points to.
 # 1104|
 # 1105|     if (der == NULL && max_len > 0)
 # 1106|->     return ASN1_VALUE_NOT_VALID;
 # 1107|
 # 1108|     counter = 0;

Signed-off-by: Simo Sorce <simo@redhat.com>
diff --git a/lib/coding.c b/lib/coding.c
index 906b079..5a947a7 100644
--- a/lib/coding.c
+++ b/lib/coding.c
@@ -1098,7 +1098,10 @@
   max_len = *len;
 
   if (der == NULL && max_len > 0)
-    return ASN1_VALUE_NOT_VALID;
+    {
+      err = ASN1_VALUE_NOT_VALID;
+      goto error;
+    }
 
   counter = 0;
   move = DOWN;