modules.useradd.get_loginclass: avoid shadowing outer info() func

************* Module salt.modules.useradd
salt/modules/useradd.py:534: [W0621(redefined-outer-name), get_loginclass] Redefining name 'info' from outer scope (line 504)
Merge pull request #15440 from hulu/useradd

modules.useradd.get_loginclass: avoid shadowing outer info() func