tcpreplay: needs MMU

Fixes:
http://autobuild.buildroot.org/results/e95f23f79ba139681fb1e51375719329afe7e22c

Signed-off-by: Gilles Talis <gilles.talis@gmail.com>
Signed-off-by: Peter Korsgaard <jacmet@sunsite.dk>

package/tcpreplay/Config.in

@@ -1,5 +1,6 @@
 config BR2_PACKAGE_TCPREPLAY
 	bool "tcpreplay"
+	depends on BR2_USE_MMU # fork()
 	select BR2_PACKAGE_LIBPCAP
 	help
 	  Tcpreplay is a tool for replaying network traffic from files saved