tests/pread64-pwrite64.c: minor cleanup

* tests/pread64-pwrite64.c: Do not include <sys/uio.h>.
diff --git a/tests/pread64-pwrite64.c b/tests/pread64-pwrite64.c
index c351c02..b1d45de 100644
--- a/tests/pread64-pwrite64.c
+++ b/tests/pread64-pwrite64.c
@@ -32,7 +32,6 @@
 #include <fcntl.h>
 #include <stdio.h>
 #include <stdlib.h>
-#include <sys/uio.h>
 #include <unistd.h>
 
 static void