pinio.c: remove duplicate #ifdef wrapping.

In case of no enable pins, these functions resolve to nothing
anyways, see pinio.h.

pinio.c

@@ -1,18 +1,10 @@
 #include	"pinio.h"
 
 void power_off() {
-	#ifdef	X_ENABLE_PIN
-		x_disable();
-	#endif
-	#ifdef	Y_ENABLE_PIN
-		y_disable();
-	#endif
-	#ifdef	Z_ENABLE_PIN
-		z_disable();
-	#endif
-	#ifdef	E_ENABLE_PIN
-		e_disable();
-	#endif
+
+	x_disable();
+	y_disable();
+	z_disable();
 
 	#ifdef	STEPPER_ENABLE_PIN
 	WRITE(STEPPER_ENABLE_PIN, STEPPER_ENABLE_INVERT ^ 1);