staging: as102: Remove redundant NULL check before release_firmware() and pointless comments

release_firmware() deals gracefullt with NULL pointers - it's
redundant to check for them before calling the function.

Also remove a few pointless comments - it's rather obvious from the
code that kfree() free's a buffer and that release_firmware() releases
firmware - comments just stating that add no value.

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