Correct an incorrect cast.

Author: PhilipHazel

ChangeLog

@@ -135,6 +135,8 @@ particular when it is serialized.
 
 25. Remove a duplication typo in pcre2_tables.c
 
+26. Correct an incorrect cast in pcre2_valid_utf.c
+
 
 Version 10.23 14-February-2017
 ------------------------------

src/pcre2_valid_utf.c

@@ -7,7 +7,7 @@ and semantics are as close as possible to those of the Perl 5 language.
 
                        Written by Philip Hazel
      Original API code Copyright (c) 1997-2012 University of Cambridge
-         New API code Copyright (c) 2016 University of Cambridge
+          New API code Copyright (c) 2016-2017 University of Cambridge
 
 -----------------------------------------------------------------------------
 Redistribution and use in source and binary forms, with or without
@@ -142,20 +142,20 @@ for (p = string; length > 0; p++)
 
   if (c < 0xc0)                         /* Isolated 10xx xxxx byte */
     {
-    *erroroffset = (int)(p - string);
+    *erroroffset = (PCRE2_SIZE)(p - string);
     return PCRE2_ERROR_UTF8_ERR20;
     }
 
   if (c >= 0xfe)                        /* Invalid 0xfe or 0xff bytes */
     {
-    *erroroffset = (int)(p - string);
+    *erroroffset = (PCRE2_SIZE)(p - string);
     return PCRE2_ERROR_UTF8_ERR21;
     }
 
   ab = PRIV(utf8_table4)[c & 0x3f];     /* Number of additional bytes (1-5) */
   if (length < ab)                      /* Missing bytes */
     {
-    *erroroffset = (int)(p - string);
+    *erroroffset = (PCRE2_SIZE)(p - string);
     switch(ab - length)
       {
       case 1: return PCRE2_ERROR_UTF8_ERR1;