avformat/pva: Check for EOF before retrying in read_part_of_packet()

Fixes: Infinite loop
Fixes: pva-4b1835dbc2027bf3c567005dcc78e85199240d06

Found-by: Paul Ch <paulcher@icloud.com>
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>
(cherry picked from commit 9807d3976b)
Signed-off-by: Michael Niedermayer <michael@niedermayer.cc>

libavformat/pva.c

@@ -134,6 +134,10 @@ recover:
             pes_flags              = avio_rb16(pb);
             pes_header_data_length = avio_r8(pb);
 
+            if (avio_feof(pb)) {
+                return AVERROR_EOF;
+            }
+
             if (pes_signal != 1 || pes_header_data_length == 0) {
                 pva_log(s, AV_LOG_WARNING, "expected non empty signaled PES packet, "
                                           "trying to recover\n");