Correct typo in zlib.h comment.

zlib.h

@@ -597,11 +597,11 @@ ZEXTERN int ZEXPORT deflateInit2(z_streamp strm,
    Z_RLE is almost as fast as Z_HUFFMAN_ONLY, but should give better
    compression for PNG image data than Huffman only.  The degree of string
    matching from most to none is: Z_DEFAULT_STRATEGY, Z_FILTERED, Z_RLE, then
-   Z_HUFFMAN. The strategy parameter affects the compression ratio but never
-   the correctness of the compressed output, even if it is not set optimally
-   for the given data.  Z_FIXED uses the default string matching, but prevents
-   the use of dynamic Huffman codes, allowing for a simpler decoder for special
-   applications.
+   Z_HUFFMAN_ONLY. The strategy parameter affects the compression ratio but
+   never the correctness of the compressed output, even if it is not set
+   optimally for the given data.  Z_FIXED uses the default string matching, but
+   prevents the use of dynamic Huffman codes, allowing for a simpler decoder
+   for special applications.
 
      deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough
    memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid