I/OAT: fixups from code comments

A few fixups from Andrew's code comments.
  - removed "static inline" forward-declares
  - changed use of min() to min_t()
  - removed some unnecessary NULL initializations
  - removed a couple of BUG() calls

Fixes this:

drivers/dma/ioat_dma.c: In function `ioat1_tx_submit':
drivers/dma/ioat_dma.c:177: sorry, unimplemented: inlining failed in call to '__ioat1_dma_memcpy_issue_pending': function body not available
drivers/dma/ioat_dma.c:268: sorry, unimplemented: called from here

Signed-off-by: Shannon Nelson <shannon.nelson@intel.com>
Cc: "Williams, Dan J" <dan.j.williams@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/dma/ioatdma.h b/drivers/dma/ioatdma.h
index b668234..f2c7fed 100644
--- a/drivers/dma/ioatdma.h
+++ b/drivers/dma/ioatdma.h
@@ -76,7 +76,7 @@
 	dma_cookie_t completed_cookie;
 	unsigned long last_completion;
 
-	u32 xfercap;	/* XFERCAP register value expanded out */
+	size_t xfercap;	/* XFERCAP register value expanded out */
 
 	spinlock_t cleanup_lock;
 	spinlock_t desc_lock;