mtdbg: Rem check prev backtrace symbol

The symbol may be repeated during recursion

Signed-off-by: Max Logaev <maxlogaev@proton.me>

programs/develop/mtdbg/mtdbg.asm

@@ -1159,10 +1159,8 @@ ends
 OnBacktrace:
         push    ebp
 
-        xor     eax, eax
-        mov     [prev_bt_sym], eax
-
         ; Set max depth counter
+        xor     eax, eax
         dec     eax
 
         mov     esi, [curarg]
@@ -1218,14 +1216,8 @@ OnBacktrace:
         ; Find symbol by return address
         call    find_near_symbol
         test    esi, esi
-        jz      .print_stub
+        jnz      .print_sym
 
-        ; The current symbol must not be equal to the previous one
-        cmp     esi, [prev_bt_sym]
-        mov     [prev_bt_sym], esi
-        jnz     .print_sym
-
-    .print_stub:
         mov     esi, aBacktraceSymStub
 
     .print_sym:
@@ -2619,7 +2611,6 @@ disasm_string           rb 256
 
 stack_frame_dump        rb sizeof.STACK_FRAME
 bt_depth                rd 1
-prev_bt_sym             rd 1
 
 ;-----------------------------------------------------------------------------
 ;                  Coordinates and sizes for GUI