Replace the specification of a data structure by a pointer dereference
as the parameter for the operator "sizeof" to make the corresponding size
determination a bit safer according to the Linux coding style convention.

This issue was detected by using the Coccinelle software.
Signed-off-by: NMarkus Elfring <elfring@users.sourceforge.net>
Acked-by: NAdam Thomson <Adam.Thomson.Opensource@diasemi.com>
Signed-off-by: NMark Brown <broonie@kernel.org>