Always include <sys/...>, not <linux/...>.

(cherry picked from commit d9979ed40e2c8d6f9596f0e1e9c64d6b8a0364cc)

Change-Id: I355f4419b4a0cab8ad52ee9a945b56d5236fb668
diff --git a/dhcpcd.c b/dhcpcd.c
index bac33f3..6eae970 100644
--- a/dhcpcd.c
+++ b/dhcpcd.c
@@ -74,7 +74,7 @@
 
 #ifdef ANDROID
 #include <sys/capability.h>
-#include <linux/prctl.h>
+#include <sys/prctl.h>
 #include <cutils/properties.h>
 #include <private/android_filesystem_config.h>
 #endif