fix backward logic bug

Author: markrypto

CMakeLists.txt

@@ -2,7 +2,7 @@ cmake_minimum_required(VERSION 3.7.2)
 
 project(KeepKeyFirmware
 
-        VERSION 7.1.5
+        VERSION 7.1.7
 
         LANGUAGES C CXX ASM)
 

tools/firmware/keepkey_main.c

@@ -95,7 +95,7 @@ static bool canDropPrivs(void) {
       // by this point already, and trying to drop privs *again* will cause a fault.
       bool sigPresent = sigindex1 >= 1 && sigindex1 <= BLK_v2_0_0_PUBKEYS;
       // delay before the security-critical branch instruction
-      return !fi_defense_delay(sigPresent);
+      return fi_defense_delay(sigPresent);
     }
   }
   __builtin_unreachable();