arch/mips/lib/board.c: Fix GCC 4.6 build warning

Fix:
board.c: In function 'board_init_r':
board.c:262:8: warning: unused variable 's' [-Wunused-variable]

(raised for configurations without ethernet support like
vct_premium_small)

Signed-off-by: Wolfgang Denk <wd@denx.de>
Cc: Shinya Kuribayashi <skuribay@ruby.dti.ne.jp>
1 file changed