[SCSI] qla4xxx: Modified debug log messages for boot info.

In some configurations user may not have boot targets configured.
In such cases the debug messages printed out by driver look like
some kind of failure happening. However this could be a valid
case, so modified the messages to appear as warning messages
versus failure messages.

Signed-off-by: Manish Rangankar <manish.rangankar@qlogic.com>
Signed-off-by: Vikas Chaudhary <vikas.chaudhary@qlogic.com>
Reviewed-by: Mike Christie <michaelc@cs.wisc.edu>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>