HF_Legic: remove global variable and cleanup

As requested by @iceman1001:
* removed global variable
* updated according to make style
* added entry in CHANGELOG.md

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]
+ - Added `HF_LEGIC` standalone mode to read and simulate a Legic prime tag (@Pizza_4u)
  - Added keri MS decode/encode and update 'lf keri clone' to support MS fc/cid cloning. (@mwalker33)
  - Fix 'hf mfdes enum' - now actually manages to enumerate files under all AID's. :smiley:  (@iceman1001)
  - Fix 'hf mfdes info' - now detects DESFire light and work properly Wrapped commands :+1: (@iceman1001)

armsrc/Standalone/hf_legic.c

@@ -61,8 +61,7 @@ void RunMod(){
             SpinDelay(1000);
             // We don't care if we read a MIM256, MIM512 or MIM1024
             // we just read 1024 bytes
-      LegicRfReader(0, 1024, 0x55);
-      read_success = check_success();
+            read_success = LegicRfReader(0, 1024, 0x55);
         } while (read_success == 0 && !BUTTON_PRESS());
 
         //simulate if read successfully

armsrc/legicrf.c

@@ -28,7 +28,6 @@
 static uint8_t *legic_mem;      /* card memory, used for read, write */
 static legic_card_select_t card;/* metadata of currently selected card */
 static crc_t legic_crc;
-int read_success = 0;
 
 //-----------------------------------------------------------------------------
 // Frame timing and pseudorandom number generator
@@ -442,10 +441,10 @@ OUT:
     StopTicks();
 }
 
-void LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv) {
+int LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv) {
+    int read_success = 0;
     // configure ARM and FPGA
     init_reader(false);
-    read_success = 0;
 
     // establish shared secret and detect card type
     uint8_t card_type = setup_phase(iv);
@@ -475,6 +474,7 @@ void LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv) {
 OUT:
     switch_off();
     StopTicks();
+    return read_success;
 }
 
 void LegicRfWriter(uint16_t offset, uint16_t len, uint8_t iv, uint8_t *data) {
@@ -515,5 +515,3 @@ OUT:
     switch_off();
     StopTicks();
 }
-
-int check_success(void){return read_success;}

armsrc/legicrf.h

@@ -15,7 +15,6 @@
 #include "common.h"
 
 void LegicRfInfo(void);
-void LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv);
+int LegicRfReader(uint16_t offset, uint16_t len, uint8_t iv);
 void LegicRfWriter(uint16_t offset, uint16_t len, uint8_t iv, uint8_t *data);
-int check_success(void);
 #endif /* __LEGICRF_H */