mtd: part: fix incorrect format specifier for an unsigned long long

An unsigned long long is being formatted with %lld instead of the unsigned
version %llu. Fix this.

Clean up cppcheck warning:
%lld in format string (no. 1) requires 'long long' but the argument type
is 'unsigned long long'.

Fixes: a62c24d7 ("mtd: part: Add sysfs variable for offset of partition")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Signed-off-by: Richard Weinberger <richard@nod.at>

drivers/mtd/mtdpart.c

@@ -572,7 +572,7 @@ static ssize_t mtd_partition_offset_show(struct device *dev,
 {
 	struct mtd_info *mtd = dev_get_drvdata(dev);
 	struct mtd_part *part = mtd_to_part(mtd);
-	return snprintf(buf, PAGE_SIZE, "%lld\n", part->offset);
+	return snprintf(buf, PAGE_SIZE, "%llu\n", part->offset);
 }
 
 static DEVICE_ATTR(offset, S_IRUGO, mtd_partition_offset_show, NULL);