Staging: bcm: Alter LOC for readability/understandability purposes

This patch alters a line of code to make it more readable
and easier to understand. The purpose of the original line
of code was to compute the amount of memory to request from
kmalloc. This mulit-step algorithm was being done in one
line of code, thus making it more difficult to understand.
Therefore, I split this algorithm into three logical steps.

Signed-off-by: Kevin McKinney <klmckinney1@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>