Fix name of "locked" variable

It's called with 0 when it's already locked, with 1 when it's not.

Reviewed-by: Andy Polyakov <appro@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>

GH: #1500

crypto/engine/eng_int.h

diff --git a/crypto/engine/eng_int.h b/crypto/engine/eng_int.h
index 741e687..f7bc706 100644
--- a/crypto/engine/eng_int.h
+++ b/crypto/engine/eng_int.h
@@ -104,7 +104,7 @@
  */
 int engine_unlocked_init(ENGINE *e);
 int engine_unlocked_finish(ENGINE *e, int unlock_for_handlers);
-int engine_free_util(ENGINE *e, int locked);
+int engine_free_util(ENGINE *e, int not_locked);
 
 /*
  * This function will reset all "set"able values in an ENGINE to NULL. This

crypto/engine/eng_lib.c

diff --git a/crypto/engine/eng_lib.c b/crypto/engine/eng_lib.c
index 8a21f38..385af54 100644
--- a/crypto/engine/eng_lib.c
+++ b/crypto/engine/eng_lib.c
@@ -67,7 +67,7 @@
     e->flags = 0;
 }
 
-int engine_free_util(ENGINE *e, int locked)
+int engine_free_util(ENGINE *e, int not_locked)
 {
     int i;
 
@@ -76,7 +76,7 @@
 #ifdef HAVE_ATOMICS
     CRYPTO_DOWN_REF(&e->struct_ref, &i, global_engine_lock);
 #else
-    if (locked)
+    if (not_locked)
         CRYPTO_atomic_add(&e->struct_ref, -1, &i, global_engine_lock);
     else
         i = --e->struct_ref;