quota: Propagate error from ->acquire_dquot()

Currently when some error happened in ->acquire_dquot(), dqget() just
returned NULL. That was indistinguishable from a case when e.g. someone
run quotaoff and so was generally silently ignored. However
->acquire_dquot() can fail because of ENOSPC or EIO in which case user
should better know. So propagate error up from ->acquire_dquot properly.

Signed-off-by: Jan Kara <jack@suse.cz>
diff --git a/fs/ocfs2/file.c b/fs/ocfs2/file.c
index 719f7f4..4d9e827 100644
--- a/fs/ocfs2/file.c
+++ b/fs/ocfs2/file.c
@@ -1209,8 +1209,8 @@
 		    && OCFS2_HAS_RO_COMPAT_FEATURE(sb,
 		    OCFS2_FEATURE_RO_COMPAT_USRQUOTA)) {
 			transfer_to[USRQUOTA] = dqget(sb, make_kqid_uid(attr->ia_uid));
-			if (!transfer_to[USRQUOTA]) {
-				status = -ESRCH;
+			if (IS_ERR(transfer_to[USRQUOTA])) {
+				status = PTR_ERR(transfer_to[USRQUOTA]);
 				goto bail_unlock;
 			}
 		}
@@ -1218,8 +1218,8 @@
 		    && OCFS2_HAS_RO_COMPAT_FEATURE(sb,
 		    OCFS2_FEATURE_RO_COMPAT_GRPQUOTA)) {
 			transfer_to[GRPQUOTA] = dqget(sb, make_kqid_gid(attr->ia_gid));
-			if (!transfer_to[GRPQUOTA]) {
-				status = -ESRCH;
+			if (IS_ERR(transfer_to[GRPQUOTA])) {
+				status = PTR_ERR(transfer_to[GRPQUOTA]);
 				goto bail_unlock;
 			}
 		}