Fix remaining non-returning Destroys()

Plus a little refactor to mining flaps and spacepod doors- they now use
CanAtmosPass instead of manually setting the turf to no-atmos-passing

code/modules/assembly/assembly.dm

@@ -70,8 +70,8 @@
 			else if(A.a_right == src)
 				A.a_right = null
 			src.holder = null
-		..()
-			
+		return ..()
+
 	pulsed(var/radio = 0)
 		if(holder && (wires & WIRE_RECEIVE))
 			activate()