dm-buffered: clean up handling of bc->start

Don't cast arguments to kstrtoull.
The test "bc->start >= (ti->len >> 1)" is not needed.

Signed-off-by: Mikulas Patocka <mpatocka@redhat.com>

---
 drivers/md/dm-buffered-target.c |   11 ++++++-----
 1 file changed, 6 insertions(+), 5 deletions(-)

Index: linux-2.6/drivers/md/dm-buffered-target.c
===================================================================
--- linux-2.6.orig/drivers/md/dm-buffered-target.c
+++ linux-2.6/drivers/md/dm-buffered-target.c
@@ -372,6 +372,7 @@ static int buffered_ctr(struct dm_target
 {
 	struct buffered_c *bc;
 	int i, r;
+	unsigned long long start;
 
 	if (argc < 2) {
 		ti->error = "Requires at least 2 arguments";
@@ -386,12 +387,12 @@ static int buffered_ctr(struct dm_target
 
 	ti->private = bc;
 
-	r = (kstrtoull(argv[1], 10, (u64 *)&bc->start) ||
-	     bc->start >= (ti->len >> 1)) ? -EINVAL : 0;
+	r = kstrtoull(argv[1], 10, &start);
 	if (r) {
 		ti->error = "Invalid sector offset";
 		goto bad;
 	}
+	bc->start = start;
 
 	for (i = 2; i < argc; i++) {
 		const char *arg = argv[i];
@@ -550,7 +551,7 @@ static void buffered_status(struct dm_ta
 
 	switch (type) {
 	case STATUSTYPE_TABLE:
-		DMEMIT("%s %llu", bc->dev->name, (u64)bc->start);
+		DMEMIT("%s %llu", bc->dev->name, (unsigned long long)bc->start);
 		if (bc->buffer_size_set)
 			DMEMIT(" block_size:%u", bc->buffer_size);
 		if (bc->discard_set)
@@ -599,7 +600,7 @@ static int buffered_message(struct dm_ta
 			    char *result, unsigned int maxlen)
 {
 	struct buffered_c *bc = ti->private;
-	sector_t n;
+	unsigned long long n;
 
 	if (!strcasecmp(argv[0], "async_flush")) {
 		if (argc != 1)
@@ -611,7 +612,7 @@ static int buffered_message(struct dm_ta
 	if (!strcasecmp(argv[0], "buffers")) {
 		if (argc != 2)
 			return -EINVAL;
-		if (kstrtoull(argv[1], 10, (u64 *)&n) || !n ||
+		if (kstrtoull(argv[1], 10, &n) || !n ||
 		    n >= _buffered_size(ti) || n > UINT_MAX)
 			return -EINVAL;
 		dm_bufio_set_minimum_buffers(bc->bufio, (unsigned int)n);