Mech repair loop line fix (#3927)

<!-- Write **BELOW** The Headers and **ABOVE** The comments else it may
not be viewable. -->
<!-- You can view Contributing.MD for a detailed description of the pull
request process. -->

## About The Pull Request

It works now

## Why It's Good For The Game

<!-- Please add a short description of why you think these changes would
benefit the game. If you can't justify it in words, it might not be
worth adding. -->

## Changelog

:cl:
fix: mech looping repairs loop now. For real.
/:cl:

<!-- Both :cl:'s are required for the changelog to work! You can put
your name to the right of the first :cl: if you want to overwrite your
GitHub username as author ingame. -->
<!-- You can use multiple of the same prefix (they're only used for the
icon ingame) and delete the unneeded ones. Despite some of the tags,
changelogs should generally represent how a player might be affected by
the changes rather than a summary of the PR's contents. -->

Signed-off-by: Theos <[email protected]>

code/game/mecha/mecha_defense.dm

@@ -309,7 +309,7 @@
 		obj_integrity += min(10 * repair_multiplier, max_integrity-obj_integrity)
 		if(obj_integrity == max_integrity)
 			to_chat(user, span_notice("It looks to be fully repaired now."))
-		return
+			return
 	to_chat(user, span_warning("The [name] is at full integrity!"))
 
 /obj/mecha/proc/mech_toxin_damage(mob/living/target)