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/game/objects/items/devices/powersink.dm

@@ -65,7 +65,7 @@
 		processing_objects.Remove(src)
 //		attached.attached = null
 		attached = null
-		..()
+		return ..()
 
 
 	attack_ai()

code/game/objects/items/shooting_range.dm

@@ -16,7 +16,7 @@
 				T.pinned_target = null
 				T.density = 1
 				break
-		..() // delete target
+		return ..() // delete target
 
 	Move()
 		..()

code/game/objects/items/weapons/implants/implant.dm

@@ -47,7 +47,7 @@
 	Destroy()
 		if(part)
 			part.implants.Remove(src)
-		..()
+		return ..()
 
 /obj/item/weapon/implant/tracking
 	name = "tracking"