The used buffers counter is not incremented in case of an error so
the counter can become negative. Increment the used buffers counter
before checking for errors.
Signed-off-by: NJan Glauber <jang@linux.vnet.ibm.com>
Signed-off-by: NFrank Blaschka <frank.blaschka@de.ibm.com>
Signed-off-by: NDavid S. Miller <davem@davemloft.net>