patch 8.2.4473: Coverity warnds for not checking return value of ftell()

Problem:    Coverity warnds for not checking return value of ftell().
Solution:   Bail out if ftell() returns a negative value.
diff --git a/src/version.c b/src/version.c
index e0384c8..7b5d66a 100644
--- a/src/version.c
+++ b/src/version.c
@@ -755,6 +755,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    4473,
+/**/
     4472,
 /**/
     4471,