clean up FORTIFY_SOURCE handling.

Avoid duplicating huge chunks of code.

Change-Id: Id6145cdfce781c5ffba2abaaa79681d25a7ab28f
diff --git a/libc/bionic/__vsprintf_chk.cpp b/libc/bionic/__vsprintf_chk.cpp
index 00010cf..e1d10f5 100644
--- a/libc/bionic/__vsprintf_chk.cpp
+++ b/libc/bionic/__vsprintf_chk.cpp
@@ -52,9 +52,7 @@
     int ret = vsnprintf(dest, dest_len_from_compiler, format, va);
 
     if ((size_t) ret >= dest_len_from_compiler) {
-        __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
-            "*** vsprintf buffer overflow detected ***\n");
-        abort();
+        __fortify_chk_fail("vsprintf buffer overflow", 0);
     }
 
     return ret;