Typo fix.

 (backport from rev. 54292)

Doc/lib/libctypes.tex

@@ -1219,7 +1219,7 @@ py_cmp_func 5 7
 It is quite interesting to see that the Windows \function{qsort} function
 needs more comparisons than the linux version!
 
-As we can easily check, our array sorted now:
+As we can easily check, our array is sorted now:
 \begin{verbatim}
 >>> for i in ia: print i,
 ...