[PATCH] x86: use mkfs.fat, sed, mmd and mcopy from staging_dir

[Florian Eckert]

Hello Felix,

>> During image generation, the host tools should not be used but the 
>> tools
>> from the staging_dir.
>> 
>> - mkfs.fat
>> - sed
>> - mmd
>> - mcopy
> Why is this necessary? $STAGING_DIR_HOST/bin should already be in
> $PATH before the host system parts.

I only noticed that the prefix $(STAGING_DIR_HOST) is missing for these 
tools on x86_64 image Makefile.
If I look for this prefix in OpenWrt, it is found in some image 
Makefiles commands.

For examples:
- 
https://github.com/openwrt/openwrt/blob/master/target/linux/realtek/image/Makefile
- 
https://github.com/openwrt/openwrt/blob/master/target/linux/bcm63xx/image/Makefile
- 
https://github.com/openwrt/openwrt/blob/master/target/linux/ath25/image/Makefile


If this is in the PATH through this line  
https://github.com/openwrt/openwrt/blob/master/Makefile, then this is 
not needed for the others?

I only wanted to unify this with the change and make it clear that the 
tool from staging is used here.


- Florian