Update X509_STORE_new.pod

Minor typo.

CLA: trivial
Reviewed-by: NRichard Levitte <levitte@openssl.org>
Reviewed-by: NMatthias St. Pierre <Matthias.St.Pierre@ncp-e.com>
(Merged from https://github.com/openssl/openssl/pull/8866)

(cherry picked from commit 3527cfcf283d2ee2e14e85f8e432eb1bcc687dbe)

doc/man3/X509_STORE_new.pod

@@ -23,7 +23,7 @@ X509_STORE_up_ref() increments the reference count associated with the
 X509_STORE object.
 
 X509_STORE_lock() locks the store from modification by other threads,
-X509_STORE_unlock() locks it.
+X509_STORE_unlock() unlocks it.
 
 X509_STORE_free() frees up a single X509_STORE object.