[PATCH] ext3: Fix missed mutex unlock

Missed unlock_super()call is added in error condition code path.

Signed-off-by: Leonid Ananiev <leonid.i.ananiev@intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>