avcodec/pgxdec: Remove pointless checks

These checks were (most likely) added to check for overreads
as the bytestream2_get_* functions return 0 in this case.
Yet this is not necessary anymore as we now have an explicit check
for the size. Should the input contain a real \0, pgx_get_number()
will error out lateron.

Reviewed-by: Paul B Mahol <onemda@gmail.com>
Signed-off-by: Andreas Rheinhardt <andreas.rheinhardt@outlook.com>

libavcodec/pgxdec.c

@@ -69,14 +69,11 @@ static int pgx_decode_header(AVCodecContext *avctx, GetByteContext *g,
     } else if (byte == '-') {
         *sign = 1;
         bytestream2_skipu(g, 1);
-    } else if (byte == 0)
-        goto error;
+    }
 
     byte = bytestream2_peek_byteu(g);
     if (byte == ' ')
         bytestream2_skipu(g, 1);
-    else if (byte == 0)
-        goto error;
 
     if (pgx_get_number(avctx, g, depth))
         goto error;