build: fix memory leaks

Fix the memory leaks found by clang-3.1

Change-Id: Iaae68627ef599c324c9c9ee5737c22e92512862d
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/775
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>

src/server/gdb_server.c

@@ -1138,6 +1138,7 @@ static int gdb_set_register_packet(struct connection *connection,
 
 	if ((unsigned int)chars != strlen(separator + 1)) {
 		LOG_ERROR("gdb sent a packet with wrong register size");
+		free(bin_buf);
 		return ERROR_SERVER_REMOTE_CLOSED;
 	}