scsi: isci: 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: ddcc7e34 ("isci: fix dma_unmap_sg usage")
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Link: https://lore.kernel.org/r/20250627142451.241713-2-fourier.thomas@gmail.com


Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>