ANDROID: sdcardfs: eliminate the offset argument to ->direct_IO

Eliminate the offset argument to sdcardfs_direct_IO() which is dropped
by upstream commit c8b8e32d ("direct-io: eliminate the offset
argument to ->direct_IO"), otherwise we run into following build error:

  CC [M]  fs/sdcardfs/mmap.o
fs/sdcardfs/mmap.c:76:15: error: initialization from incompatible pointer type [-Werror=incompatible-pointer-types]
  .direct_IO = sdcardfs_direct_IO,
               ^
fs/sdcardfs/mmap.c:76:15: note: (near initialization for ‘sdcardfs_aops.direct_IO’)

Change-Id: I292d93bb16365a9fa46494accb2b5da51028b5c1
Signed-off-by: Amit Pundir <amit.pundir@linaro.org>