make image which width is the integral multiple of mcu width work

[MROS]

原本採用"大於"，當寬度剛好為mcu整數倍時，會將下一個mcu放在同一行，導致這一行多了一個mcu

originally use ">", if image width is the multiple of mcu width, it will put next mcu in the same line, which cause this line have extra mcu