scsi/NCR5380: dprintk macro

This is the delta between the two submissions:
[PATCH 00/12] scsi/NCR5380: fix debugging macros and #include structure
and
[PATCH v2 00/12] scsi/NCR5380: fix debugging macros and #include structure

The macro definition changes were discussed on the mailing list during
review. The idea is to get the compiler to check the parameters of
disabled printk() calls so that the debugging code doesn't rot again.

Signed-off-by: Finn Thain <fthain@telegraphics.com.au>
Signed-off-by: Christoph Hellwig <hch@lst.de>