patch 9.0.0373: Coverity warns for NULL check and unused return value

Problem:    Coverity warns for NULL check and unused return value.
Solution:   Remove the NULL check, it was already checked earlier.  Add (void)
            to ignore the return value.
diff --git a/src/version.c b/src/version.c
index 0209280..c768302 100644
--- a/src/version.c
+++ b/src/version.c
@@ -708,6 +708,8 @@
 static int included_patches[] =
 {   /* Add new patch number below this line */
 /**/
+    373,
+/**/
     372,
 /**/
     371,