scratch: remove quick validity check

Roll back fix for github issue #350

About Scratch Usage:
For compile time, scratch space is strongly recommended to be
allocated immediately after database generation.
For runtime, besides using scratch for corresponding database,
Hyperscan also allows user to use larger scratch space allocated
for another database.
When multiple concurrent threads need to use the same databases
and a new scratch space is required, cloning the largest one is
always safe. This is realized based on API hs_scratch_size() and
hs_clone_scratch().
Behaviors beyond above are discouraged and results are undefined.

src/state.h

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 2015-2022, Intel Corporation
+ * Copyright (c) 2015-2023, Intel Corporation
  *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions are met:
@@ -57,9 +57,6 @@ struct hs_stream {
 
     /** \brief The current stream offset. */
     u64a offset;
-
-    /** \brief Identity of hs_stream, for scratch validity check. */
-    u32 crc32;
 };
 
 #define getMultiState(hs_s)      ((char *)(hs_s) + sizeof(*(hs_s)))