mem: Use Packet writing functions instead of memcpy

Classes were using memcpy instead of the Packet functions
created for writing to/from the packet. This allows these
writes to be better checked and tracked.

This also fixes a bug in MemCheckerMonitor, which was using
the incorrect type for the packet pointer.

Change-Id: I5bbc8a24e59464e8219bb6d54af8209e6d4ee1af
Signed-off-by: Daniel R. Carvalho <odanrc@yahoo.com.br>
Reviewed-on: https://gem5-review.googlesource.com/c/13695
Reviewed-by: Nikos Nikoleris <nikos.nikoleris@arm.com>
Maintainer: Nikos Nikoleris <nikos.nikoleris@arm.com>

src/mem/cache/base.cc

@@ -861,10 +861,9 @@ BaseCache::satisfyRequest(PacketPtr pkt, CacheBlk *blk, bool, bool)
         if (pkt->isAtomicOp()) {
             // extract data from cache and save it into the data field in
             // the packet as a return value from this atomic op
-
             int offset = tags->extractBlkOffset(pkt->getAddr());
             uint8_t *blk_data = blk->data + offset;
-            std::memcpy(pkt->getPtr<uint8_t>(), blk_data, pkt->getSize());
+            pkt->setData(blk_data);
 
             // execute AMO operation
             (*(pkt->getAtomicOp()))(blk_data);