[PATCH v2] staging: fbtft: differentiate between buffer and data types to fix sparse warning

sparse was complaning about an incorrect type cast: drivers/staging/fbtft/fbtft-bus.c:60:1: warning: incorrect type in assignment (different base types) drivers/staging/fbtft/fbtft-bus.c:60:1:expected unsigned short [unsigned] [short] [usertype] drivers/staging/fbtft/fbtft-bus.c:60:1:

[PATCH v2] staging: fbtft: differentiate between buffer and data types to fix sparse warning

sparse was complaning about an incorrect type cast: drivers/staging/fbtft/fbtft-bus.c:60:1: warning: incorrect type in assignment (different base types) drivers/staging/fbtft/fbtft-bus.c:60:1:expected unsigned short [unsigned] [short] [usertype] drivers/staging/fbtft/fbtft-bus.c:60:1: