libltpvdso: Add check for getauxval()

The getauxval() function have been added into glibc 2.19 and hence is
not present in Centos 6.

Signed-off-by: Cyril Hrubis <chrubis@suse.cz>
diff --git a/configure.ac b/configure.ac
index 05032d1..81804fd 100644
--- a/configure.ac
+++ b/configure.ac
@@ -87,6 +87,7 @@
     fsopen \
     fspick \
     fstatat \
+    getauxval \
     getdents \
     getdents64 \
     io_pgetevents \
diff --git a/libs/libltpvdso/vdso_helpers.c b/libs/libltpvdso/vdso_helpers.c
index e958403..6352700 100644
--- a/libs/libltpvdso/vdso_helpers.c
+++ b/libs/libltpvdso/vdso_helpers.c
@@ -9,11 +9,13 @@
 
 #include "parse_vdso.h"
 #include <sys/auxv.h>
+#include "config.h"
 
 static unsigned long sysinfo_ehdr;
 
 static void vdso_init(void)
 {
+#ifdef HAVE_GETAUXVAL
 	if (sysinfo_ehdr)
 		return;
 
@@ -24,6 +26,9 @@
 	}
 
 	vdso_init_from_sysinfo_ehdr(sysinfo_ehdr);
+#else
+	tst_res(TINFO, "getauxval() not supported");
+#endif /* HAVE_GETAUXVAL */
 }
 
 void find_clock_gettime_vdso(gettime_t *ptr_vdso_gettime,