Staging: bcm: Fix semaphore locking error when downloading firmware.

This patch releases semaphore locks when
an error occurrs while attempting to
download firmware for the bcm driver.
When downloading firmware for this driver,
a process is expected to call
the following ioctl's in this order:
(1)IOCTL_BCM_BUFFER_DOWNLOAD_START,
(2)IOCTL_BCM_BUFFER_DOWNLOAD, and (3)
IOCTL_BCM_BUFFER_DOWNLOAD_STOP.
Semaphore, “Adapter->fw_download_sema” is
expected to be acquired in the first ioctl,
IOCTL_BCM_BUFFER_DOWNLOAD_START, and it should
block until IOCTL_BCM_BUFFER_DOWNLOAD_STOP
is called.  In this case, if an error
occurred before STOP finished, the semaphore
"Adapter->fw_download_sema" was not being released.

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