mtd: mtdram.h: checkpatch cleanup

include/linux/mtd/mtdram.h:6: ERROR: code indent should use tabs where possible
Signed-off-by: NAndrea Gelmini <andrea.gelmini@gelma.net>
Signed-off-by: NArtem Bityutskiy <Artem.Bityutskiy@nokia.com>
Signed-off-by: NDavid Woodhouse <David.Woodhouse@intel.com>