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/file.c b/fs/ubifs/file.c
index 3f254e3..3594aae 100644
--- a/fs/ubifs/file.c
+++ b/fs/ubifs/file.c
@@ -212,7 +212,7 @@
  */
 static void release_existing_page_budget(struct ubifs_info *c)
 {
-	struct ubifs_budget_req req = { .dd_growth = c->page_budget};
+	struct ubifs_budget_req req = { .dd_growth = c->bi.page_budget};
 
 	ubifs_release_budget(c, &req);
 }
@@ -1189,7 +1189,7 @@
 	if (budgeted)
 		ubifs_release_budget(c, &req);
 	else {
-		c->nospace = c->nospace_rp = 0;
+		c->bi.nospace = c->bi.nospace_rp = 0;
 		smp_wmb();
 	}
 	return err;