dmaengine: axi-dmac: Small code cleanup

Use a for() loop instead of a while() loop in axi_dmac_fill_linear_sg().
This makes the code leaner and cleaner overall, and does not introduce
any functional change.

Signed-off-by: Paul Cercueil <paul@crapouillou.net>
Link: https://lore.kernel.org/r/20231215131313.23840-2-paul@crapouillou.net


Signed-off-by: Vinod Koul <vkoul@kernel.org>