INT 2F U - DOS 3+ internal - CLOSE CURRENT FILE
AX = 1201h
SS = DOS DS (must be using a DOS internal stack)
SDA current SFT pointer -> SFT of file to close
Return: CF set on error
BX???
CX new reference count of SFT
ES:DI -> SFT for file
SeeAlso: AX=1227h,INT 21/AH=3Eh

See also: 2F1106

2F1201 - DOS 3+ internal - CLOSE CURRENT FILE