Fix dma_unmap_sg() nents value

The dma_unmap_sg() functions should be called with the same nents as the
dma_map_sg(), not the value the map function returned.

Fixes: ed10435d ("RDMA/erdma: Implement hierarchical MTT")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Link: https://patch.msgid.link/20250630092346.81017-2-fourier.thomas@gmail.com


Signed-off-by: Leon Romanovsky <leon@kernel.org>