fix hf 15 readmulti - wrong block count number. It is decreased before to be zero based, but in calc we need number of blocks

CHANGELOG.md

@@ -3,6 +3,7 @@ All notable changes to this project will be documented in this file.
 This project uses the changelog in accordance with [keepchangelog](http://keepachangelog.com/). Please use this to write notable changes, which is not the same as git commit log...
 
 ## [unreleased][unreleased]
+- Fixed `hf 15 readmulti` - fix block calculations (@iceman1001)
 - Changed `mem load` - now handles UL-C and UL-AES dictionary files (@iceman1001)
 - Changed `hf mfu sim` - now support UL-C simulation (@iceman1001)
 - Added `!` - run system commands from inside the client. Potentially dangerous if running client as SUDO, SU, ROOT (@iceman1001)

client/src/cmdhf15.c

@@ -2274,7 +2274,7 @@ static int CmdHF15Readmulti(const char *Cmd) {
     ISO15_ERROR_HANDLING_CARD_RESPONSE(d, resp.length)
 
     // 1 byte cmd,  1 lock byte,  4 / 8 bytes block size,  2 crc
-    if (resp.length > (1 + (blockcnt * (blocksize + 1)) + 2)) {
+    if (resp.length > (1 + ((blockcnt + 1) * (blocksize + 1)) + 2)) {
         PrintAndLogEx(WARNING, "got longer response. Check block size!");
     }