staging: bcm2835-audio: allocate enough data for work queues

We accidentally allocate sizeof(void *) bytes instead of 112 bytes.  It
results in memory corruption.

Fixes: 23b028c8 ("staging: bcm2835-audio: initial staging submission")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>