Get rid of the warning about not used return value from chdir.

https://github.com/DinoTools/dionaea/issues/162

https://github.com/DinoTools/dionaea/pull/163

Merged in in https://github.com/DinoTools/dionaea/commit/ea5d54060af53250abfe3dde9f36af399fa30524

diff -ru dionaea-793accd84432a77309fa8b81e1f5e9b5bd9ee7a3.orig/src/dionaea.c dionaea-793accd84432a77309fa8b81e1f5e9b5bd9ee7a3.new/src/dionaea.c

--- dionaea-793accd84432a77309fa8b81e1f5e9b5bd9ee7a3.orig/src/dionaea.c	2018-03-21 04:21:30.201354584 +0100

+++ dionaea-793accd84432a77309fa8b81e1f5e9b5bd9ee7a3.new/src/dionaea.c	2018-03-21 04:22:07.529846514 +0100

@@ -723,7 +723,10 @@

 			g_error("Could not chroot(\"%s\") (%s)", opt->root, strerror(errno));

 		} else

 		{

-			chdir("/");

+			if ( chdir("/") != 0 ) {

+				g_error("Could change to root directory '/' ... this shuoldn't happen exitting.\nErr: (%s)", strerror(errno));

+				return EXIT_FAILURE;

+			}

 		}

 	}