avcodec/ccaption_dec: Fix mixed declaration and statement.

Found-by: ubitux
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavcodec/ccaption_dec.c

@@ -714,8 +714,9 @@ static void process_cc608(CCaptionSubContext *ctx, int64_t pts, uint8_t hi, uint
         handle_char(ctx, hi, lo, pts);
         ctx->prev_cmd[0] = ctx->prev_cmd[1] = 0;
     } else if (hi == 0x17 && lo >= 0x21 && lo <= 0x23) {
+        int i;
         /* Tab offsets (spacing) */
-        for (int i = 0; i < lo - 0x20; i++) {
+        for (i = 0; i < lo - 0x20; i++) {
             handle_char(ctx, ' ', 0, pts);
         }
     } else {