[SCSI] sg: remove unnecessary indentation

blocking is de-facto a constant and the now-removed comment wasn't all
that useful either.  Without them and the resulting indentation the code
is a bit nicer to read.

Signed-off-by: Joern Engel <joern@logfs.org>
Acked-by: Douglas Gilbert <dgilbert@interlog.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>