curl_share_setopt.3: refer to CURLSHOPT_USERDATA(3) properly

Author: bagder

docs/libcurl/curl_share_setopt.3

@@ -39,8 +39,7 @@ See \fICURLSHOPT_SHARE(3)\fP.
 .IP CURLSHOPT_UNSHARE
 See \fICURLSHOPT_UNSHARE(3)\fP.
 .IP CURLSHOPT_USERDATA
-The \fIparameter\fP allows you to specify a pointer to data that will be passed
-to the lock_function and unlock_function each time it is called.
+See \fICURLSHOPT_USERDATA(3)\fP.
 .SH EXAMPLE
 .nf
   CURLSHcode sh