patch 8.2.0167: Coverity warning for ignoring return value

Problem:    Coverity warning for ignoring return value.
Solution:   Check the return value and jump if failed.
diff --git a/src/vim9execute.c b/src/vim9execute.c
index 001d274..6865ba1 100644
--- a/src/vim9execute.c
+++ b/src/vim9execute.c
@@ -556,7 +556,8 @@
 
 		    if (ga_grow(&ectx.ec_stack, 1) == FAIL)
 			goto failed;
-		    get_option_tv(&name, &optval, TRUE);
+		    if (get_option_tv(&name, &optval, TRUE) == FAIL)
+			goto failed;
 		    *STACK_TV_BOT(0) = optval;
 		    ++ectx.ec_stack.ga_len;
 		}