Fix possible c&p mistake when checking the presence of `queue_full` attribute
in old kernels. There should be no impact on how the tool works other than
exiting gracefully in case the attribute does not exist.
Fixes: #21
Signed-off-by: Rafael Fonseca <r4f4rfs@gmail.com>
Signed-off-by: Steffen Maier <maier@linux.vnet.ibm.com>
Signed-off-by: Michael Holzheu <holzheu@linux.vnet.ibm.com>