pnm: cosmetics: reindent

Signed-off-by: Paul B Mahol <onemda@gmail.com>

libavcodec/pnm.c

@@ -126,7 +126,7 @@ int ff_pnm_decode_header(AVCodecContext *avctx, PNMContext * const s)
                 avctx->pix_fmt = AV_PIX_FMT_GRAY8A;
         } else if (depth == 3) {
             if (maxval < 256) {
-            avctx->pix_fmt = AV_PIX_FMT_RGB24;
+                avctx->pix_fmt = AV_PIX_FMT_RGB24;
             } else {
                 avctx->pix_fmt = AV_PIX_FMT_RGB48BE;
             }