Include <xlocale.h> for macOS, take II.

Fix typo in macro name.

Discussion: https://postgr.es/m/CA%2BhUKG%2Bk-o3N_SyNJNJpAcdtMo_HheN30miAeXehk9yw%3D9WYzA%40mail.gmail.com

Author: macdice

src/port/chklocale.c

@@ -23,7 +23,7 @@
 #include <langinfo.h>
 #endif
 
-#ifdef LOCALE_T_IN_XLOCALE_H
+#ifdef LOCALE_T_IN_XLOCALE
 #include <xlocale.h>
 #endif