Makefile: Fix the flash-to-device helper rules

Makefile

@@ -64,16 +64,17 @@ BAUD=115200
 DEV=/dev/ttyUSB0
 SUDO=sudo
 STM32FLASH=stm32flash
+T=out/$(target)/greaseweazle/target.hex
 
 ocd: FORCE all
 	$(PYTHON) scripts/telnet.py localhost 4444 \
-	"reset init ; flash write_image erase `pwd`/$(target)/$(target).hex ; reset"
+	"reset init ; flash write_image erase `pwd`/$(T) ; reset"
 
 f1_ocd: FORCE all
-	$(PYTHON) scripts/openocd/flash.py `pwd`/$(target)/$(target).hex
+	$(PYTHON) scripts/openocd/flash.py `pwd`/$(T)
 
 flash: FORCE all
-	$(SUDO) $(STM32FLASH) -b $(BAUD) -w $(target)/$(target).hex $(DEV)
+	$(SUDO) $(STM32FLASH) -b $(BAUD) -w $(T) $(DEV)
 
 start: FORCE
 	$(SUDO) $(STM32FLASH) -b $(BAUD) -g 0 $(DEV)