test/helpers: remove error.h include

Not available on musl...

Fixes: 604ad00 ("test/helpers: add O_NONBLOCK set/clear helpers")
Signed-off-by: Jens Axboe <axboe@kernel.dk>

Author: axboe

test/helpers.c

@@ -14,7 +14,6 @@
 #include <arpa/inet.h>
 #include <netinet/ip.h>
 #include <netinet/tcp.h>
-#include <error.h>
 
 #include "helpers.h"
 #include "liburing.h"