Remove the ifdef around ec.h's ec_key.h compatibility include

It doesn't actually do anything.

Change-Id: I8a5748dc86b842406cc656a5b251e1a7c0092377
Reviewed-on: https://boringssl-review.googlesource.com/6090
Reviewed-by: Adam Langley <alangley@gmail.com>
Reviewed-by: Adam Langley <agl@google.com>
diff --git a/include/openssl/ec.h b/include/openssl/ec.h
index 004c949..b632646 100644
--- a/include/openssl/ec.h
+++ b/include/openssl/ec.h
@@ -325,9 +325,7 @@
 
 
 /* Old code expects to get EC_KEY from ec.h. */
-#if !defined(OPENSSL_HEADER_EC_KEY_H)
 #include <openssl/ec_key.h>
-#endif
 
 
 #if defined(__cplusplus)