Staging, bcm: Remove unnecessary casts of void ptr returning alloc function return values

Here's a patch against a copy of linux-next that I just cloned.

Don't pointlessly cast pointers returned by allocation functions that
return void pointers which are implicitly converted.
For drivers/staging/bcm/

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>