8046408: Build failure from multiple ptrace.h

Summary: prefer <sys/ptrace.h> over <linux/ptrace.h>
Reviewed-by: sla, mikael
Contributed-by: kim.barrett@oracle.com

agent/src/os/linux/libproc.h

@@ -34,7 +34,7 @@
 #include "libproc_md.h"
 #endif
 
-#include <linux/ptrace.h>
+#include <sys/ptrace.h>
 
 /************************************************************************************