[SCSI] Signdness issue in drivers/scsi/osst.c

another signdness warning from gcc 4.1

drivers/scsi/osst.c:5154: warning: comparison of unsigned expression < 0 is always false

The problem is that blk is defined as unsigned, but all usages of it are
normal int cases.  osst_get_frame_position() and osst_get_sector() return ints
and can return negative values.  If blk stays an unsigned int, the error check
is useless.

Signed-off-by: Eric Sesterhenn <snakebyte@gmx.de>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>