net: axi_emac: Fix timeout test

net: axi_emac: Fix timeout test

The timeout test in axi_dma_init is not correct due to the
post-decrement used on the timeout variable which will mean timeout is
not 0 if the timeout occurs. Make the timeout variable an int instead of
a u32 and then test for timeout being -1.

This issue was found by Smatch.

Signed-off-by: Andrew Goodbody <andrew.goodbody@linaro.org>
Link: https://lore.kernel.org/r/20250806-net_xilinx_axi-v2-1-6311cf59451d@linaro.org
Signed-off-by: Michal Simek <michal.simek@amd.com>