Fix builds where _FORTIFY_SOURCE is off.

Also add a more intention-revealing guard so we don't have loads of
places checking whether our inlining macro is defined.

Change-Id: I168860cedcfc798b07a5145bc48a125700265e47
diff --git a/libc/include/sys/cdefs.h b/libc/include/sys/cdefs.h
index 3617aba..1976d6a 100644
--- a/libc/include/sys/cdefs.h
+++ b/libc/include/sys/cdefs.h
@@ -516,13 +516,14 @@
 #include <android/api-level.h>
 
 #if defined(_FORTIFY_SOURCE) && _FORTIFY_SOURCE > 0 && defined(__OPTIMIZE__) && __OPTIMIZE__ > 0 && !defined(__clang__)
+#define __BIONIC_FORTIFY 1
 #define __BIONIC_FORTIFY_INLINE \
     extern inline \
     __attribute__ ((always_inline)) \
     __attribute__ ((gnu_inline)) \
     __attribute__ ((artificial))
-#define __BIONIC_FORTIFY_UNKNOWN_SIZE ((size_t) -1)
 #endif
+#define __BIONIC_FORTIFY_UNKNOWN_SIZE ((size_t) -1)
 
 /* Android-added: for FreeBSD's libm. */
 #define __weak_reference(sym,alias) \
diff --git a/libc/include/sys/stat.h b/libc/include/sys/stat.h
index 05b221f..4e8beb6 100644
--- a/libc/include/sys/stat.h
+++ b/libc/include/sys/stat.h
@@ -129,7 +129,7 @@
 extern int    mknod(const char *, mode_t, dev_t);
 extern mode_t umask(mode_t);
 
-#if defined(__BIONIC_FORTIFY_INLINE)
+#if defined(__BIONIC_FORTIFY)
 
 extern mode_t __umask_chk(mode_t);
 extern mode_t __umask_real(mode_t)
@@ -147,7 +147,7 @@
   }
   return __umask_chk(mode);
 }
-#endif /* defined(__BIONIC_FORTIFY_INLINE) */
+#endif /* defined(__BIONIC_FORTIFY) */
 
 
 #define  stat64    stat