rust: Minor nit fixing

I stumbled upon this and I am not sure what I was thinking.

Signed-off-by: Xiangfei Ding <xfding@google.com>
Change-Id: Ifbb091bdaf8d726a4781543b255225d36a6a6964
Reviewed-on: https://boringssl-review.googlesource.com/c/boringssl/+/100307
Presubmit-BoringSSL-Verified: boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com <boringssl-scoped@luci-project-accounts.iam.gserviceaccount.com>
Reviewed-by: David Benjamin <davidben@google.com>

rust/bssl-tls/src/methods.rs

diff --git a/rust/bssl-tls/src/methods.rs b/rust/bssl-tls/src/methods.rs
index 0efd790..2d0ed4c 100644
--- a/rust/bssl-tls/src/methods.rs
+++ b/rust/bssl-tls/src/methods.rs
@@ -29,11 +29,11 @@
     _argl: c_long,
     _argp: *mut c_void,
 ) {
+    if ptr.is_null() {
+        return;
+    }
     abort_on_panic(move || {
         let _ = unsafe {
-            if ptr.is_null() {
-                return;
-            }
             // Safety: the data was boxed and stored via SSL_CTX_set_ex_data.
             Box::from_raw(ptr as *mut M)
         };