Replace ‘jp [hl]’ with ‘jp hl’

The former is arguably misleading (as you don’t access the memory location in hl to retrieve the jump location), and is consequently deprecated in newer versions of rgbds.

This fix silences these deprecation warnings.

engine/debug.asm

@@ -305,7 +305,7 @@ Function81a74: ; 81a74
 	ld a, [hli]
 	ld h, [hl]
 	ld l, a
-	jp [hl]
+	jp hl
 
 .asm_81a9a
 	call Function81eca
@@ -611,7 +611,7 @@ Function81cc2: ; 81cc2
 	ld a, [hli]
 	ld h, [hl]
 	ld l, a
-	jp [hl]
+	jp hl
 
 .asm_81cdf
 	ld a, $4
@@ -1353,7 +1353,7 @@ Function822f0: ; 822f0
 	ld a, [hli]
 	ld h, [hl]
 	ld l, a
-	jp [hl]
+	jp hl
 ; 82301
 
 .dw ; 82301