Patch: use a new __NR_perf_event_open macro introduced in linux 2.6.32

[Arseniy Alekseyev <rotsor gmail com>]

Dear sysprof,

Please make use of a new __NR_perf_event_open macro (renamed
__NR_perf_counter_open) when compiled with newer linux kernels.

Please find the patch below.

Thank you.
Arseniy.

--- a/collector.c
+++ b/collector.c
@@ -151,7 +151,9 @@ sysprof_perf_counter_open (struct perf_event_attr *attr,
                           unsigned long           flags)
 {
 #ifndef __NR_perf_counter_open
-#if defined(__i386__)
+#ifdef __NR_perf_event_open
+#define __NR_perf_counter_open __NR_perf_event_open
+#elif defined(__i386__)
 #define __NR_perf_counter_open 336
 #elif defined(__x86_64__)
 #define __NR_perf_counter_open 298