build: remove clang unused variable assignment warnings

Change-Id: Ibe5254704d6cd879a318a82c4f50d9da3c14276c
Signed-off-by: Spencer Oliver <spen@spen-soft.co.uk>
Reviewed-on: http://openocd.zylin.com/600
Tested-by: jenkins
Reviewed-by: Freddie Chopin <freddie.chopin@gmail.com>

src/target/target.c

@@ -5058,7 +5058,6 @@ static int jim_target_smp(Jim_Interp *interp, int argc, Jim_Obj *const *argv)
 	struct target_list *head, *curr, *new;
 	curr = (struct target_list *) NULL;
 	head = (struct target_list *) NULL;
-	new = (struct target_list *) NULL;
 
 	retval = 0;
 	LOG_DEBUG("%d", argc);