Fix typo.

ChangeLog

@@ -37,7 +37,7 @@ Changes in 1.2.7.1 (24 Mar 2013)
 - Clean up the usage of z_const and respect const usage within zlib
 - Clean up examples/gzlog.[ch] comparisons of different types
 - Avoid shift equal to bits in type (caused endless loop)
-- Fix unintialized value bug in gzputc() introduced by const patches
+- Fix uninitialized value bug in gzputc() introduced by const patches
 - Fix memory allocation error in examples/zran.c [Nor]
 - Fix bug where gzopen(), gzclose() would write an empty file
 - Fix bug in gzclose() when gzwrite() runs out of memory