Update system.c

Correct control pin state checking within pin change interrupt. Improper if-else statements could lead to missed signal.

Author: chamnit

grbl/system.c

@@ -66,13 +66,15 @@ ISR(CONTROL_INT_vect)
   if (pin) {
     if (bit_istrue(pin,CONTROL_PIN_INDEX_RESET)) {
       mc_reset();
-    } else if (bit_istrue(pin,CONTROL_PIN_INDEX_CYCLE_START)) {
+    }
+    if (bit_istrue(pin,CONTROL_PIN_INDEX_CYCLE_START)) {
       bit_true(sys_rt_exec_state, EXEC_CYCLE_START);
+    }
     #ifndef ENABLE_SAFETY_DOOR_INPUT_PIN
-      } else if (bit_istrue(pin,CONTROL_PIN_INDEX_FEED_HOLD)) {
+      if (bit_istrue(pin,CONTROL_PIN_INDEX_FEED_HOLD)) {
         bit_true(sys_rt_exec_state, EXEC_FEED_HOLD);
     #else
-      } else if (bit_istrue(pin,CONTROL_PIN_INDEX_SAFETY_DOOR)) {
+      if (bit_istrue(pin,CONTROL_PIN_INDEX_SAFETY_DOOR)) {
         bit_true(sys_rt_exec_state, EXEC_SAFETY_DOOR);
     #endif
     }