For io_tlb_nslabs, the debugfs code reports the correct value for a
specific reserved memory pool. But for io_tlb_used, the value reported
is always for the default pool, not the specific reserved pool. Fix this.
Fixes: 5c850d31880e ("swiotlb: fix passing local variable to debugfs_create_ulong()") Signed-off-by: Michael Kelley <mikelley@microsoft.com> Signed-off-by: Christoph Hellwig <hch@lst.de> Signed-off-by: Sasha Levin <sashal@kernel.org>