Fix alignment errors in hashtable fuzzer

we extract several values (uint16_t and uint64_t from the fuzzer buff
passed in, but they weren't aligned on 2 and 8 byte boundaries.  Adjust
the fuzzer to use the proper offsets

Fixes #24272

fuzz/hashtable.c

@@ -133,7 +133,7 @@ int FuzzerTestOneInput(const uint8_t *buf, size_t len)
      * 1 byte to detect the operation to preform, 2 bytes
      * for the lookup key, and 8 bytes of value
      */
-    if (len < 11) {
+    if (len < 20) {
         skipped_values++;
         return -1;
     }
@@ -142,7 +142,7 @@ int FuzzerTestOneInput(const uint8_t *buf, size_t len)
      * parse out our operation flags and key
      */
     op_flags = buf[0];
-    keyval = *((uint16_t *)&buf[1]);
+    keyval = *((uint16_t *)&buf[2]);
 
     /*
      * Initialize our key
@@ -177,7 +177,7 @@ int FuzzerTestOneInput(const uint8_t *buf, size_t len)
                 rc_prediction = 0;
         }
 
-        valptr->value = *(uint64_t *)&buf[3];
+        valptr->value = *(uint64_t *)&buf[8];
         /*
          * do the insert/replace
          */