ext4: Fix for ext4_mb_collect_stats()

Fix ext4_mb_collect_stats() to use the correct test for s_bal_success; it
should be testing "best-extent.fe_len >= orig-extent.fe_len" , not
"orig-extent.fe_len >= goal-extent.fe_len" .
Signed-off-by: NCurt Wohlgemuth <curtw@google.org>
Signed-off-by: N"Theodore Ts'o" <tytso@mit.edu>

fs/ext4/mballoc.c

@@ -3029,7 +3029,7 @@ static void ext4_mb_collect_stats(struct ext4_allocation_context *ac)
 	if (sbi->s_mb_stats && ac->ac_g_ex.fe_len > 1) {
 		atomic_inc(&sbi->s_bal_reqs);
 		atomic_add(ac->ac_b_ex.fe_len, &sbi->s_bal_allocated);
-		if (ac->ac_o_ex.fe_len >= ac->ac_g_ex.fe_len)
+		if (ac->ac_b_ex.fe_len >= ac->ac_o_ex.fe_len)
 			atomic_inc(&sbi->s_bal_success);
 		atomic_add(ac->ac_found, &sbi->s_bal_ex_scanned);
 		if (ac->ac_g_ex.fe_start == ac->ac_b_ex.fe_start &&