Clean up XXX comments for unused content

mobile/fixed_words.asm

@@ -33,8 +33,7 @@ Function11c075: ; 11c075
 	ret
 ; 11c082
 
-Function11c082: ; 11c082
-; XXX
+Unreferenced_Function11c082: ; 11c082
 	push de
 	ld a, c
 	call Function11c254

mobile/mobile_45.asm

@@ -7350,7 +7350,7 @@ INCBIN "data/mobile/ascii-sym.txt"
 
 ; everything from here to the end of the bank is related to the
 ; Mobile Stadium option from the continue/newgame menu.
-; XXX better function names
+; Needs better function names
 MobileStudium: ; 0x117a7f
 	ld a, [hInMenu]
 	push af

mobile/news/news.asm

@@ -1,9 +1,8 @@
 ; http://forums.glitchcity.info/index.php?topic=7509.msg206449#msg206449
 
-	db $cc, $6b, $1e ; XXX
+	db $cc, $6b, $1e ; unused
 
-Function1f4003: ; 1f4003
-; XXX
+Unreferenced_Function1f4003: ; 1f4003
 	ld a, $6
 	call GetSRAMBank
 	ld hl, .news_data
@@ -16,8 +15,7 @@ Function1f4003: ; 1f4003
 .news_data
 INCBIN "mobile/news/news_1.bin"
 
-Function1f4dbe: ; 1f4dbe
-; XXX
+Unreferenced_Function1f4dbe: ; 1f4dbe
 	ld a, $6
 	call GetSRAMBank
 	ld hl, .news_data