FORTIFY_SOURCE: Add __FD_* checks

Add FORTIFY_SOURCE checks for the following macros:

* FD_CLR
* FD_ISSET
* FD_SET

Bug: 11047121
Change-Id: I3c5952136aec9eff3288b91b1318677ff971525c
diff --git a/libc/Android.mk b/libc/Android.mk
index fc61c27..c7478c5 100644
--- a/libc/Android.mk
+++ b/libc/Android.mk
@@ -188,6 +188,7 @@
 
 # Fortify implementations of libc functions.
 libc_common_src_files += \
+    bionic/__FD_chk.cpp \
     bionic/__fgets_chk.cpp \
     bionic/__memcpy_chk.cpp \
     bionic/__memmove_chk.cpp \