Adds a missing check for an error return code from scsi_sysfs_add_sdev.
This resolves entry #4863 in the OSDL bugzilla.  Although in that bug
report the failure occurred because of a confusion over scanning vs.
rescanning, in general add_sdev can fail for a number of reasons (the
simplest being insufficient memory) and the caller should cope properly.
Signed-off-by: NAlan Stern <stern@rowland.harvard.edu>
Cc: James Bottomley <James.Bottomley@SteelEye.com>
Signed-off-by: NAndrew Morton <akpm@osdl.org>
Signed-off-by: NLinus Torvalds <torvalds@osdl.org>