Convert the struct i2c_msg initialization to C99 format. This makes
maintaining and editing the code simpler. Also helps once other fields
like transferred are added in future.

Thanks to Julia Lawall <julia.lawall@lip6.fr>  for automating the
conversion.
Signed-off-by: NShubhrajyoti D <shubhrajyoti@ti.com>
Acked-by: NJean Delvare <khali@linux-fr.org>
Signed-off-by: NDmitry Torokhov <dmitry.torokhov@gmail.com>