Enable -Wfortify-source

Fixes: 315245071
Change-Id: Ic8ca6a1c0dafea62f2bca3d20f5c86b3e3225ea0
diff --git a/cc/config/global.go b/cc/config/global.go
index 16b5e09..12c1bb9 100644
--- a/cc/config/global.go
+++ b/cc/config/global.go
@@ -365,8 +365,6 @@
 		"-Wno-unqualified-std-cast-call",
 		"-Wno-array-parameter",
 		"-Wno-gnu-offsetof-extensions",
-		// TODO: Enable this warning http://b/315245071
-		"-Wno-fortify-source",
 	}
 
 	llvmNextExtraCommonGlobalCflags = []string{