smsc9420: fix another postfixed timeout
smsc9420: fix another postfixed timeout

Roel Kluin recently fixed several instances where variables reach -1,
but 0 is tested afterwards.  This patch fixes another, so the timeout
will be correctly detected and a warning printed.

Signed-off-by: Steve Glendinning <99263d2cb5601ab4c3ecc128cb043592cdad6c65@smsc.com>
Signed-off-by: David S. Miller <fe08d3c717adf2ae63592e4c9aec6e3e404d8e3e@davemloft.net>

KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs,TeamVee-Kanas/android_kernel_samsung_kanas,KristFoundation/Programs