FORTIFY_SOURCE: introduce __BIONIC_FORTIFY_UNKNOWN_SIZE macro

Replace all occurances of "(size_t) -1" with a
__BIONIC_FORTIFY_UNKNOWN_SIZE macro.

Change-Id: I0b188f6cf31417d2dbef0e1bd759de3f9782873a

libc/include/sys/cdefs.h

@@ -507,6 +507,7 @@
     __attribute__ ((always_inline)) \
     __attribute__ ((gnu_inline)) \
     __attribute__ ((artificial))
+#define __BIONIC_FORTIFY_UNKNOWN_SIZE ((size_t) -1)
 #endif
 
 #endif /* !_SYS_CDEFS_H_ */