[SCSI] qla2xxx: Use less stack to emit logging messages.

Return early when logging level too low.
Use normal kernel codeing style for function braces.
Add const where appropriate to logging functions.
Remove now unused #define QL_DBG_BUF_LEN.

Signed-off-by: Joe Perches <joe@perches.com>
Signed-off-by: Saurav Kashyap <saurav.kashyap@qlogic.com>
Signed-off-by: Chad Dupuis <chad.dupuis@qlogic.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>