I believe coverity is complaining that the current code does not handle the
realloc fail case, in which case the original pointer is not freed, but NULL is
returned. The code assert()s it's not failed but that is not strong enough it
needs to abort which XREALLOC does and is a better integration into FRR-inrfa
anyway.
Signed-off-by: Christian Hopps <chopps@labn.net>