NAND: Rename DEBUG to MTDDEBUG to avoid namespace pollution.

This is particularly problematic now that non-NAND-specific code is
including <nand.h>, and thus all debugging code is being compiled
regardless of whether it was requested, as reported by Scott McNutt
<smcnutt@psyent.com>.

Signed-off-by: Scott Wood <scottwood@freescale.com>
diff --git a/drivers/mtd/onenand/onenand_bbt.c b/drivers/mtd/onenand/onenand_bbt.c
index 5a610ee..87344ab 100644
--- a/drivers/mtd/onenand/onenand_bbt.c
+++ b/drivers/mtd/onenand/onenand_bbt.c
@@ -156,9 +156,9 @@
 	block = (int)(offs >> (bbm->bbt_erase_shift - 1));
 	res = (bbm->bbt[block >> 3] >> (block & 0x06)) & 0x03;
 
-	DEBUG(MTD_DEBUG_LEVEL2,
-	      "onenand_isbad_bbt: bbt info for offs 0x%08x: (block %d) 0x%02x\n",
-	      (unsigned int)offs, block >> 1, res);
+	MTDDEBUG (MTD_DEBUG_LEVEL2,
+	          "onenand_isbad_bbt: bbt info for offs 0x%08x: (block %d) 0x%02x\n",
+	          (unsigned int)offs, block >> 1, res);
 
 	switch ((int)res) {
 	case 0x00: