🐛 Fix HAS_KILL && SOFT_RESET_ON_KILL soft reset button logic (#22269)

Marlin/src/MarlinCore.cpp

   #if EITHER(HAS_KILL, SOFT_RESET_ON_KILL)
 
     // Wait for both KILL and ENC to be released
-    while (TERN0(HAS_KILL, !kill_state()) || TERN0(SOFT_RESET_ON_KILL, !ui.button_pressed()))
+    while (TERN0(HAS_KILL, kill_state()) || TERN0(SOFT_RESET_ON_KILL, ui.button_pressed()))
       watchdog_refresh();
 
-    // Wait for either KILL or ENC press
-    while (TERN1(HAS_KILL, kill_state()) && TERN1(SOFT_RESET_ON_KILL, ui.button_pressed()))
+    // Wait for either KILL or ENC to be pressed again
+    while (TERN1(HAS_KILL, !kill_state()) && TERN1(SOFT_RESET_ON_KILL, !ui.button_pressed()))
       watchdog_refresh();
 
     // Reboot the board