remove 2 redundant calls to rb_str_dup

Because `rb_class_path` calls `rb_str_dup` already.

Closes: https://github.com/ruby/ruby/pull/2232

1 files changed, 1 insertions, 1 deletions

diff --git a/error.c b/error.c
index 19265f65cb..ffe34afc11 100644
--- a/error.c
+++ b/error.c
@@ -1098,7 +1098,7 @@ exc_inspect(VALUE exc)
     klass = CLASS_OF(exc);
     exc = rb_obj_as_string(exc);
     if (RSTRING_LEN(exc) == 0) {
-	return rb_str_dup(rb_class_name(klass));
+	return rb_class_name(klass);
     }
 
     str = rb_str_buf_new2("#<");