octeontx2: Fix otx2_dma_map_page() error return code

0 is a valid DMA address [1] so using it as the error value can lead to
errors.  The error value of dma_map_XXX() functions is DMA_MAPPING_ERROR
which is ~0.  The callers of otx2_dma_map_page() use dma_mapping_error()
to test the return value of otx2_dma_map_page(). This means that they
would not detect an error in otx2_dma_map_page().

Make otx2_dma_map_page() return the raw value of dma_map_page_attrs().

[1] https://lore.kernel.org/all/f977f68b-cec5-4ab7-b4bd-2cf6aca46267@intel.com

Fixes: caa2da3 ("octeontx2-pf: Initialize and config queues")
Cc: <stable@vger.kernel.org>
Signed-off-by: Thomas Fourier <fourier.thomas@gmail.com>
Link: https://patch.msgid.link/20260114123107.42387-2-fourier.thomas@gmail.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Author: Thomas-fourier

drivers/net/ethernet/marvell/octeontx2/nic/otx2_common.h

@@ -940,13 +940,8 @@ static inline dma_addr_t otx2_dma_map_page(struct otx2_nic *pfvf,
 					   size_t offset, size_t size,
 					   enum dma_data_direction dir)
 {
-	dma_addr_t iova;
-
-	iova = dma_map_page_attrs(pfvf->dev, page,
+	return dma_map_page_attrs(pfvf->dev, page,
 				  offset, size, dir, DMA_ATTR_SKIP_CPU_SYNC);
-	if (unlikely(dma_mapping_error(pfvf->dev, iova)))
-		return (dma_addr_t)NULL;
-	return iova;
 }
 
 static inline void otx2_dma_unmap_page(struct otx2_nic *pfvf,