Fix implicit declaration of function 'prctl' in adb.

Change-Id: I9f14cabbb36d658510c11833b3314565a2445e10
diff --git a/adb.c b/adb.c
index 90bdbaa..2c7793d 100644
--- a/adb.c
+++ b/adb.c
@@ -37,8 +37,8 @@
 #include <cutils/properties.h>
 #include <private/android_filesystem_config.h>
 #include <sys/capability.h>
-#include <linux/prctl.h>
 #include <sys/mount.h>
+#include <sys/prctl.h>
 #include <getopt.h>
 #include <selinux/selinux.h>
 #else