400947 - thread unsafe operation in PKIX_PL_HashTable_Add cause selfserv to crash. r=nelson

security/nss/lib/libpkix/pkix_pl_nss/system/pkix_pl_hashtable.c

@@ -237,6 +237,8 @@ PKIX_PL_HashTable_Add(
                     (key, &keyComp, plContext),
                     PKIX_OBJECTRETRIEVEEQUALSCALLBACKFAILED);
 
+        PKIX_MUTEX_LOCK(ht->tableLock);
+
         PKIX_CHECK(pkix_pl_PrimHashTable_GetBucketSize
                 (ht->primHash,
                 hashCode,
@@ -258,8 +260,6 @@ PKIX_PL_HashTable_Add(
                 PKIX_DECREF(deletedValue);
         }
 
-        PKIX_MUTEX_LOCK(ht->tableLock);
-
         PKIX_CHECK(pkix_pl_PrimHashTable_Add
                 (ht->primHash,
                 (void *)key,