Define MAXHOSTNAMELEN explicitly in source files.

Bug: 19093777
Bug: 19092844
Change-Id: I0778507ca2d5c008abb9a6d6315d0909263a8817
diff --git a/libc/kernel/uapi/asm-generic/param.h b/libc/kernel/uapi/asm-generic/param.h
index aa21864..6bde154 100644
--- a/libc/kernel/uapi/asm-generic/param.h
+++ b/libc/kernel/uapi/asm-generic/param.h
@@ -29,5 +29,6 @@
 #ifndef NOGROUP
 #define NOGROUP (- 1)
 #endif
-#endif
+#define MAXHOSTNAMELEN 64
 /* WARNING: DO NOT EDIT, AUTO-GENERATED CODE - SEE TOP FOR INSTRUCTIONS */
+#endif