btrfs: Make get_extent_t take btrfs_inode

In addition to changing the signature, this patch also switches
all the functions which are used as an argument to also take btrfs_inode.
Namely those are: btrfs_get_extent and btrfs_get_extent_filemap.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index d210829..c3abf84 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -2860,7 +2860,7 @@
 		*em_cached = NULL;
 	}
 
-	em = get_extent(inode, page, pg_offset, start, len, 0);
+	em = get_extent(BTRFS_I(inode), page, pg_offset, start, len, 0);
 	if (em_cached && !IS_ERR_OR_NULL(em)) {
 		BUG_ON(*em_cached);
 		atomic_inc(&em->refs);
@@ -3373,7 +3373,7 @@
 							 page_end, NULL, 1);
 			break;
 		}
-		em = epd->get_extent(inode, page, pg_offset, cur,
+		em = epd->get_extent(BTRFS_I(inode), page, pg_offset, cur,
 				     end - cur + 1, 1);
 		if (IS_ERR_OR_NULL(em)) {
 			SetPageError(page);
@@ -4338,7 +4338,7 @@
 		if (len == 0)
 			break;
 		len = ALIGN(len, sectorsize);
-		em = get_extent(inode, NULL, 0, offset, len, 0);
+		em = get_extent(BTRFS_I(inode), NULL, 0, offset, len, 0);
 		if (IS_ERR_OR_NULL(em))
 			return em;