initctl: show, use '-' for runlevels service is not member of

This patch adds a '-' for each runlevel a service/task is not part of.
The resulting listings are easier to read and also makes it clearer to
the user what happens when changing runlevels.

Signed-off-by: Joachim Nilsson <troglobit@gmail.com>

src/initctl.c

@@ -445,6 +445,8 @@ char *runlevel_string(int runlevel, int levels)
 
 			if (runlevel == i)
 				pos = strlcat(lvl, "\e[0m", sizeof(lvl));
+		} else {
+			lvl[pos++] = '-';
 		}
 	}