turkic_lc: Use utf8_to-uv_or_die not utf8_to_uvchr_buf

Author: khwilliamson

utf8.c

@@ -4290,7 +4290,7 @@ S_turkic_lc(pTHX_ const U8 * const p0, const U8 * const e,
             /* For the dot above to modify the 'I', it must be part of a
              * combining sequence immediately following the 'I', and no other
              * modifier with a ccc of 230 may intervene */
-            cp = utf8_to_uvchr_buf(p, e, NULL);
+            cp = utf8_to_uv_or_die(p, e, NULL);
             if (! _invlist_contains_cp(PL_CCC_non0_non230, cp)) {
                 break;
             }