virinitctl: Provide a stub list of init fifos for non-Linux

The virInitctlFifos list is exported, but lacks definition for
non-Linux and/or non-BSD case.
Signed-off-by: NMichal Privoznik <mprivozn@redhat.com>

src/util/virinitctl.c

@@ -184,6 +184,11 @@ virInitctlSetRunLevel(const char *fifo,
     return ret;
 }
 #else
+/* On non-Linux and non-BSD there are no known inits */
+const char *virInitctlFifos[] = {
+  NULL
+};
+
 int virInitctlSetRunLevel(const char *fifo ATTRIBUTE_UNUSED,
                           virInitctlRunLevel level ATTRIBUTE_UNUSED)
 {