staging/csr: remove firmware pointer check before giving to release_firmware

we do a check of firmware pointer against the NULL value before we give
it to the release_firmware.

as release_firmware is actually having a check against NULL, its not needed
here.

Signed-off-by: Devendra Naga <develkernel412222@gmail.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>