Fix local variables in macros

Underscore breaks local variable use in pio driver

Source/HBIOS/hbios.asm

@@ -2303,7 +2303,7 @@ HB_BADINTCNT	.DB	0
 	CALL PRTHEXBYTE
 	PRTS("H: $")
 	
-	CALL	_REGDMP
+	CALL	XREGDMP
 	;CALL	CONTINUE
 	OR	$FF			; SIGNAL INTERRUPT HANDLED
 	RET

Source/HBIOS/util.asm

@@ -328,17 +328,17 @@ PANIC:
 	LD	DE,STR_PANIC
 	CALL	WRITESTR
 	POP	DE
-	CALL	_REGDMP			; DUMP REGISTERS
+	CALL	XREGDMP			; DUMP REGISTERS
 	CALL	CONTINUE		; CHECK W/ USER
 	RET
 ;
 ;
 ;
 REGDMP:
-	CALL	_REGDMP
+	CALL	XREGDMP
 	RET
 ;
-_REGDMP:
+XREGDMP:
 	EX	(SP),HL			; RET ADR TO HL, SAVE HL ON TOS
 	LD	(REGDMP_RET),HL		; SAVE RETURN ADDRESS
 	POP	HL			; RESTORE HL AND BURN STACK ENTRY