UBIFS: introduce a separate structure for budgeting info

This patch separates out all the budgeting-related information
from 'struct ubifs_info' to 'struct ubifs_budg_info'. This way the
code looks a bit cleaner. However, the main driver for this is
that we want to save budgeting information and print it later,
so a separate data structure for this is helpful.

This patch is a preparation for the further debugging output
improvements.

Signed-off-by: Artem Bityutskiy <Artem.Bityutskiy@nokia.com>
diff --git a/fs/ubifs/find.c b/fs/ubifs/find.c
index 1d54383..2559d17 100644
--- a/fs/ubifs/find.c
+++ b/fs/ubifs/find.c
@@ -252,8 +252,8 @@
 		 * But if the index takes fewer LEBs than it is reserved for it,
 		 * this function must avoid picking those reserved LEBs.
 		 */
-		if (c->min_idx_lebs >= c->lst.idx_lebs) {
-			rsvd_idx_lebs = c->min_idx_lebs -  c->lst.idx_lebs;
+		if (c->bi.min_idx_lebs >= c->lst.idx_lebs) {
+			rsvd_idx_lebs = c->bi.min_idx_lebs -  c->lst.idx_lebs;
 			exclude_index = 1;
 		}
 		spin_unlock(&c->space_lock);
@@ -276,7 +276,7 @@
 			pick_free = 0;
 	} else {
 		spin_lock(&c->space_lock);
-		exclude_index = (c->min_idx_lebs >= c->lst.idx_lebs);
+		exclude_index = (c->bi.min_idx_lebs >= c->lst.idx_lebs);
 		spin_unlock(&c->space_lock);
 	}
 
@@ -501,8 +501,8 @@
 
 	/* Check if there are enough empty LEBs for commit */
 	spin_lock(&c->space_lock);
-	if (c->min_idx_lebs > c->lst.idx_lebs)
-		rsvd_idx_lebs = c->min_idx_lebs -  c->lst.idx_lebs;
+	if (c->bi.min_idx_lebs > c->lst.idx_lebs)
+		rsvd_idx_lebs = c->bi.min_idx_lebs -  c->lst.idx_lebs;
 	else
 		rsvd_idx_lebs = 0;
 	lebs = c->lst.empty_lebs + c->freeable_cnt + c->idx_gc_cnt -