clean up FORTIFY_SOURCE handling.

Avoid duplicating huge chunks of code.

Change-Id: Id6145cdfce781c5ffba2abaaa79681d25a7ab28f
diff --git a/libc/bionic/__umask_chk.cpp b/libc/bionic/__umask_chk.cpp
index df066b2..e1bc96d 100644
--- a/libc/bionic/__umask_chk.cpp
+++ b/libc/bionic/__umask_chk.cpp
@@ -43,9 +43,7 @@
  */
 extern "C" mode_t __umask_chk(mode_t mode) {
     if ((mode & 0777) != mode) {
-        __libc_android_log_print(ANDROID_LOG_FATAL, "libc",
-            "*** FORTIFY_SOURCE: umask called with invalid mask ***\n");
-        abort();
+        __fortify_chk_fail("umask called with invalid mask", 0);
     }
 
     return umask(mode);