iio_stresstest: was including <sys/sysctl.h> by accident.

The GNU C Library version 2.30 includes:
The Linux-specific <sys/sysctl.h> header and the sysctl function have
been deprecated and will be removed from a future version of glibc.
Application should directly access /proc instead.

iio_stresstest was not actually using anything, so remove it.

Signed-off-by: Robin Getz <[email protected]>

Author: rgetz

tests/iio_stresstest.c

@@ -28,7 +28,6 @@
 #include <errno.h>
 #include <limits.h>
 #include <sys/time.h>
-#include <sys/sysctl.h>
 
 #include "iio_common.h"