Fix the following error with clang
error: unused function 'nicvf_mbox_msg_str'
The function nicvf_mbox_msg_str() may be unused, based on DEBUG
compilation option selected. Mark __attribute__((unused)) on
this function, to inform compiler that this function may be unused
Fixes: 966e225c2396 ("net/thunderx/base: add mailbox for PF/VF communication")
Signed-off-by: Jerin Jacob <jerin.jacob@caviumnetworks.com>
Reported-by: Ferruh Yigit <ferruh.yigit@intel.com>
714b319f11