Fix bug in frame decompress example

The decompression was failing as the srcEnd pointer in
decompress_file_internal was wrongly computed beyond
the end of the memory block.
We need to account for the fact that the header ("info")
was already read in the calling function ("alreadyConsumed").

examples/frameCompress.c

@@ -260,7 +260,7 @@ decompress_file_allocDst(FILE* f_in, FILE* f_out,
     int const decompressionResult = decompress_file_internal(
                         f_in, f_out,
                         dctx,
-                        src, srcCapacity, readSize, consumedSize,
+                        src, srcCapacity, readSize-consumedSize, consumedSize,
                         dst, dstCapacity);
 
     free(dst);