hfsplus: Clear volume header pointers on failure

The next patch will use NULL volume header to determine whether
to flush the superblock. Also fix two failure cases so they
clear the headers before exiting.

Signed-Off-By: Chuck Ebbert <cebbert@redhat.com>

--- vanilla-2.6.38-rc2-git9.orig/fs/hfsplus/wrapper.c
+++ vanilla-2.6.38-rc2-git9/fs/hfsplus/wrapper.c
@@ -167,7 +167,7 @@ reread:
 		break;
 	case cpu_to_be16(HFSP_WRAP_MAGIC):
 		if (!hfsplus_read_mdb(sbi->s_vhdr, &wd))
-			goto out;
+			goto out_free_backup_vhdr;
 		wd.ablk_size >>= HFSPLUS_SECTOR_SHIFT;
 		part_start += wd.ablk_start + wd.embed_start * wd.ablk_size;
 		part_size = wd.embed_count * wd.ablk_size;
@@ -179,7 +179,7 @@ reread:
 		 * (should do this only for cdrom/loop though)
 		 */
 		if (hfs_part_find(sb, &part_start, &part_size))
-			goto out;
+			goto out_free_backup_vhdr;
 		goto reread;
 	}
 
@@ -230,8 +230,10 @@ reread:
 
 out_free_backup_vhdr:
 	kfree(sbi->s_backup_vhdr);
+	sbi->s_backup_vhdr = NULL;
 out_free_vhdr:
 	kfree(sbi->s_vhdr);
+	sbi->s_vhdr = NULL;
 out:
 	return error;
 }