include/linux/zutil.h: fix usage example of zlib_adler32()

alder32 was renamed to zlib_adler32 since before 2.6.11.
Signed-off-by: NAnish Bhatt <anish@chelsio.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

include/linux/zutil.h

@@ -68,10 +68,10 @@ typedef uLong (*check_func) (uLong check, const Byte *buf,
    An Adler-32 checksum is almost as reliable as a CRC32 but can be computed
    much faster. Usage example:
 
-     uLong adler = adler32(0L, NULL, 0);
+     uLong adler = zlib_adler32(0L, NULL, 0);
 
      while (read_buffer(buffer, length) != EOF) {
-       adler = adler32(adler, buffer, length);
+       adler = zlib_adler32(adler, buffer, length);
      }
      if (adler != original_adler) error();
 */