Remove duplicated code

Change-Id: I1b7c8165162e835e22cf164cce989c0cebd7ca95

vp8/vp8_cx_iface.c

diff --git a/vp8/vp8_cx_iface.c b/vp8/vp8_cx_iface.c
index 19e9d270..11d244f 100644
--- a/vp8/vp8_cx_iface.c
+++ b/vp8/vp8_cx_iface.c
@@ -751,9 +751,6 @@
     if (!ctx->cfg.rc_target_bitrate)
         return res;
 
-    if (!ctx->cfg.rc_target_bitrate)
-        return res;
-
     if (img)
         res = validate_img(ctx, img);