[MTD] [NAND] Fix compiler warning in Alauda driver

drivers/mtd/nand/alauda.c: In function 'alauda_bounce_read':
drivers/mtd/nand/alauda.c:412: warning: comparison of distinct pointer types lacks a cast

Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: David Woodhouse <dwmw2@infradead.org>
diff --git a/drivers/mtd/nand/alauda.c b/drivers/mtd/nand/alauda.c
index 2c29854..257937c 100644
--- a/drivers/mtd/nand/alauda.c
+++ b/drivers/mtd/nand/alauda.c
@@ -408,7 +408,7 @@
 	*retlen = len;
 	while (len) {
 		u8 oob[16];
-		u32 byte = from & al->bytemask;
+		size_t byte = from & al->bytemask;
 		size_t cplen = min(len, mtd->writesize - byte);
 
 		err = alauda_read_page(mtd, from, bounce_buf, oob,