[libpng16] Undo faulty attempt to stifle oss-fuzz complaint about

png_icc_check_tabler()
diff --git a/png.c b/png.c
index 8274f6d..343704e 100644
--- a/png.c
+++ b/png.c
@@ -816,14 +816,14 @@
 #else
 #  ifdef __STDC__
    return PNG_STRING_NEWLINE \
-      "libpng version 1.6.33beta04 - September 14, 2017" PNG_STRING_NEWLINE \
+      "libpng version 1.6.33beta04 - September 16, 2017" PNG_STRING_NEWLINE \
       "Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson" \
       PNG_STRING_NEWLINE \
       "Copyright (c) 1996-1997 Andreas Dilger" PNG_STRING_NEWLINE \
       "Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc." \
       PNG_STRING_NEWLINE;
 #  else
-   return "libpng version 1.6.33beta04 - September 14, 2017\
+   return "libpng version 1.6.33beta04 - September 16, 2017\
       Copyright (c) 1998-2002,2004,2006-2017 Glenn Randers-Pehrson\
       Copyright (c) 1996-1997 Andreas Dilger\
       Copyright (c) 1995-1996 Guy Eric Schalnat, Group 42, Inc.";
@@ -2208,18 +2208,15 @@
    png_uint_32 tag_count = png_get_uint_32(profile+128);
    png_uint_32 itag;
    png_const_bytep tag = profile+132; /* The first tag */
-   png_uint_32 tag_start = 0;
-   png_uint_32 tag_id = 0;
-   png_uint_32 tag_length = 0;
 
    /* First scan all the tags in the table and add bits to the icc_info value
     * (temporarily in 'tags').
     */
    for (itag=0; itag < tag_count; ++itag, tag += 12)
    {
-      tag_id = png_get_uint_32(tag+0);
-      tag_length = png_get_uint_32(tag+8);/* not padded */
-      tag_start = png_get_uint_32(tag+4); /* must be aligned */
+      png_uint_32 tag_id = png_get_uint_32(tag+0);
+      png_uint_32 tag_length = png_get_uint_32(tag+8);/* not padded */
+      png_uint_32 tag_start = png_get_uint_32(tag+4); /* must be aligned */
 
       /* The ICC specification does not exclude zero length tags, therefore the
        * start might actually be anywhere if there is no data, but this would be