Fix condition for using SIOCDEVPRIVATE ioctls

[danfruehauf]

On el9, SIOCDEVPRIVATE was backported to be used on kernel 5.14.x. Fix current condition that assumes this is present only on 5.15.0 and newer

Fixes #74 #67

[Alexxstud]

Hello, @danfruehauf. On 5.14.0-70.30.1.el9_0.x86_64 I am getting errno: 99, Cannot assign requested address for this PR

[danfruehauf]

Hey @Alexxstud, thanks for testing it!

Have you made sure the driver is reloaded? It works for us, and also can be tested using:

$ exanic-config enp2s0d7

Or any other interface...

Before that patch, it fails to find specific interfaces using names (this is the actual fix). Can you please test exanic-config against a specific interfaces? Cheers

[tklinchik]

It appears that on EL9 It exanic_netdev_siocdevprivate is being called instead of exanic_netdev_ioctl for SIOCGHWTSTAMP, SIOCSHWTSTAMP, EXAIOCGHWTSTAMP which results in inability to set/get timestamps on file descriptors since doing so is contingent on a result of those calls.