qlogic: get rid of a redundant test for NULL before call to release_firmware()

Since release_firmware() deals gracefully with being passed a NULL
pointer there is no reason to test explicitly before calling the
function.

Signed-off-by: Jesper Juhl <jj@chaosbits.net>
Signed-off-by: Jiri Kosina <jkosina@suse.cz>