Use <sys/prctl.h> instead of <linux/prctl.h>.

Change-Id: I708da00e36a9da8be9184c451453774be6b78c06
diff --git a/libcutils/sched_policy.c b/libcutils/sched_policy.c
index fa0792f..f8ffb1d 100644
--- a/libcutils/sched_policy.c
+++ b/libcutils/sched_policy.c
@@ -39,17 +39,9 @@
 
 #if defined(HAVE_ANDROID_OS) && defined(HAVE_SCHED_H) && defined(HAVE_PTHREADS)
 
-#include <linux/prctl.h>
-#include <sched.h>
 #include <pthread.h>
-
-#ifndef SCHED_NORMAL
-  #define SCHED_NORMAL 0
-#endif
-
-#ifndef SCHED_BATCH
-  #define SCHED_BATCH 3
-#endif
+#include <sched.h>
+#include <sys/prctl.h>
 
 #define POLICY_DEBUG 0