[libpng16] Revise contrib/oss-fuzz/build.sh links to other oss-fuzz files

contrib/oss-fuzz/build.sh

@@ -38,10 +38,13 @@ make -j$(nproc) libpng16.la
 
 # build libpng_read_fuzzer.
 $CXX $CXXFLAGS -std=c++11 -I. \
-     $SRC/libpng_read_fuzzer.cc -o $OUT/libpng_read_fuzzer \
+     $SRC/libpng/contrib/oss-fuzz/libpng_read_fuzzer.cc -o \
+     $OUT/libpng_read_fuzzer \
      -lFuzzingEngine .libs/libpng16.a -lz
 
 # add seed corpus.
-find $SRC/libpng/contrib/pngsuite -name "*.png" | xargs zip $OUT/libpng_read_fuzzer_seed_corpus.zip
+find $SRC/libpng/contrib/pngsuite -name "*.png" | \
+   xargs zip $OUT/libpng_read_fuzzer_seed_corpus.zip
 
-cp $SRC/*.dict $SRC/*.options $OUT/
+cp $SRC/libpng/contrib/oss-fuzz*.dict \
+   $SRC/libpng/contrib/oss-fuzz/*.options $OUT/