patch 8.2.2094: when an expression fails getting next command may be wrong

Problem:    When an expression fails getting the next command may be wrong.
Solution:   Do not check for a next command after :eval fails. (closes #7415)
diff --git a/src/eval.c b/src/eval.c
index 2232510..47aaaad 100644
--- a/src/eval.c
+++ b/src/eval.c
@@ -2156,7 +2156,10 @@
 		&& called_emsg == called_emsg_before
 		&& (flags & EVAL_CONSTANT) == 0)
 	    semsg(_(e_invexpr2), arg);
-	ret = FAIL;
+
+	// Some of the expression may not have been consumed.  Do not check for
+	// a next command to avoid more errors.
+	return FAIL;
     }
 
     if (eap != NULL)