udhcpc: kill undocumented -W, it was a no-op.

 fix option parsing in the case some CONFIG_x are off.
 disable -b on NOMMU, make backgrounding work correctly
 (if a bit differently from MMU case). Previously,
 it wasn't working at all.
 stop using global data for flags in main(), opt
 bitfield works as well.

function                                             old     new   delta
cryptpw_main                                         177     153     -24
packed_usage                                       24478   24452     -26
client_background                                     26       -     -26
udhcpc_main                                         2462    2372     -90
------------------------------------------------------------------------------
(add/remove: 0/1 grow/shrink: 0/3 up/down: 0/-166)           Total: -166 bytes

1 files changed, 0 insertions, 2 deletions

diff --git a/include/platform.h b/include/platform.h
index 21224fabf..cdc1151ad 100644
--- a/include/platform.h
+++ b/include/platform.h
@@ -248,12 +248,10 @@ typedef unsigned smalluint;
     (defined __UCLIBC__ && __UCLIBC_MAJOR__ >= 0 && __UCLIBC_MINOR__ >= 9 && \
     __UCLIBC_SUBLEVEL__ > 28 && !defined __ARCH_USE_MMU__)
 #define BB_MMU 0
-#define BB_NOMMU 1
 #define USE_FOR_NOMMU(...) __VA_ARGS__
 #define USE_FOR_MMU(...)
 #else
 #define BB_MMU 1
-/* BB_NOMMU is not defined in this case! */
 #define USE_FOR_NOMMU(...)
 #define USE_FOR_MMU(...) __VA_ARGS__
 #endif