perl: Rename database_get_vendor() to get_vendor(9

This function is being called on the database object, so it makes
sense to call it this as it is shorter.
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

src/perl/Location/Location.xs

@@ -84,7 +84,7 @@ get_country_code(db, address)
 
 
 const char*
-database_get_vendor(db)
+get_vendor(db)
 	struct loc_database* db;
 
 	CODE: