[XFS] fix sparse shadowed variable warnings

- in xfs_probe_cluster rename the inner len to pg_len. There's no harm
  here because the outer len isn't used after the inner len comes into
  existence but it keeps the code clean.
- in xfs_da_do_buf remove the inner i because they don't overlap
  and they are both the same type.

SGI-PV: 968555
SGI-Modid: xfs-linux-melb:xfs-kern:29311a

Signed-off-by: Christoph Hellwig <hch@infradead.org>
Signed-off-by: David Chinner <dgc@sgi.com>
Signed-off-by: Tim Shimmin <tes@sgi.com>
diff --git a/fs/xfs/linux-2.6/xfs_aops.c b/fs/xfs/linux-2.6/xfs_aops.c
index fd4105d..d9c40fe 100644
--- a/fs/xfs/linux-2.6/xfs_aops.c
+++ b/fs/xfs/linux-2.6/xfs_aops.c
@@ -652,7 +652,7 @@
 
 		for (i = 0; i < pagevec_count(&pvec); i++) {
 			struct page *page = pvec.pages[i];
-			size_t pg_offset, len = 0;
+			size_t pg_offset, pg_len = 0;
 
 			if (tindex == tlast) {
 				pg_offset =
@@ -665,16 +665,16 @@
 				pg_offset = PAGE_CACHE_SIZE;
 
 			if (page->index == tindex && !TestSetPageLocked(page)) {
-				len = xfs_probe_page(page, pg_offset, mapped);
+				pg_len = xfs_probe_page(page, pg_offset, mapped);
 				unlock_page(page);
 			}
 
-			if (!len) {
+			if (!pg_len) {
 				done = 1;
 				break;
 			}
 
-			total += len;
+			total += pg_len;
 			tindex++;
 		}