suricata: unix-socket mode and -l are compatible

Commit 93642a0d1d did prevent to
specify the logging directory on command line and use the unix
socket.

It looks like the implementation has evolved and the arbitrary
limitation can be removed allowing a user to start unix socket
without editing the configuration file.

src/suricata.c

@@ -1840,12 +1840,6 @@ static TmEcode ParseCommandLine(int argc, char** argv, SCInstance *suri)
         return TM_ECODE_FAILED;
     }
 
-    if ((suri->run_mode == RUNMODE_UNIX_SOCKET) && suri->set_logdir) {
-        SCLogError(SC_ERR_INITIALIZATION,
-                "can't use -l and unix socket runmode at the same time");
-        return TM_ECODE_FAILED;
-    }
-
     /* save the runmode from the commandline (if any) */
     suri->aux_run_mode = suri->run_mode;