Remove unnecessary NULL checks, part 3.

Finish up the e's.

Change-Id: Iabb8da000fbca6efee541edb469b90896f60d54b
Reviewed-on: https://boringssl-review.googlesource.com/4516
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/crypto/ex_data.c b/crypto/ex_data.c
index 8f199fd..10fefc8 100644
--- a/crypto/ex_data.c
+++ b/crypto/ex_data.c
@@ -306,10 +306,8 @@
 
   sk_CRYPTO_EX_DATA_FUNCS_free(func_pointers);
 
-  if (ad->sk) {
-    sk_void_free(ad->sk);
-    ad->sk = NULL;
-  }
+  sk_void_free(ad->sk);
+  ad->sk = NULL;
 }
 
 void CRYPTO_cleanup_all_ex_data(void) {}