Fix mismatched free/delete

Bug #65553
diff --git a/poppler/UTF.cc b/poppler/UTF.cc
index 42c7836..46007b7 100644
--- a/poppler/UTF.cc
+++ b/poppler/UTF.cc
@@ -101,7 +101,7 @@
         utf16[i] = (s[2 + i*2] & 0xff) << 8 | (s[3 + i*2] & 0xff);
       }
       len = UTF16toUCS4(utf16, len, &u);
-      delete utf16;
+      delete[] utf16;
     } else {
       u = NULL;
     }