Revert "Removed flexible array usage due to error on g++ 10.x"

This reverts commit e843822.

Author: bbogush

qt/cmd.h

@@ -64,6 +64,7 @@ typedef struct __attribute__((__packed__))
 {
     Cmd cmd;
     uint8_t len;
+    uint8_t data[];
 } WriteDataCmd;
 
 typedef struct __attribute__((__packed__))
@@ -135,6 +136,7 @@ typedef struct __attribute__((__packed__))
 {
     uint8_t code;
     uint8_t info;
+    uint8_t data[];
 } RespHeader;
 
 typedef struct __attribute__((__packed__))

qt/reader.cpp

@@ -159,7 +159,6 @@ int Reader::handleStatus(uint8_t *pbuf, uint32_t len)
 int Reader::handleData(uint8_t *pbuf, uint32_t len)
 {
     RespHeader *header = reinterpret_cast<RespHeader *>(pbuf);
-    uint8_t *data = pbuf + sizeof(RespHeader);
     uint8_t dataSize = header->info;
     size_t headerSize = sizeof(RespHeader), packetSize = headerSize + dataSize;
 
@@ -179,7 +178,7 @@ int Reader::handleData(uint8_t *pbuf, uint32_t len)
         return -1;
     }
 
-    memcpy(rbuf + readOffset, data, dataSize);
+    memcpy(rbuf + readOffset, header->data, dataSize);
     readOffset += dataSize;
     bytesRead += dataSize;