brctl: code shrink

brctl: code shrink

function                                             old     new   delta
show_bridge                                          323     317      -6
brctl_main                                          2171    2164      -7
------------------------------------------------------------------------------
(add/remove: 0/0 grow/shrink: 0/2 up/down: 0/-13)             Total: -13 bytes
   text	   data	    bss	    dec	    hex	filename
1002083	    551	   5612	1008246	  f6276	busybox_old
1002065	    551	   5612	1008228	  f6264	busybox_unstripped

Signed-off-by: Denys Vlasenko <vda.linux@googlemail.com>