ipatests: set selinux context for fips mode
    
    In order to test FIPS mode, the test is faking a user-space
    FIPS environment by creating a file /var/tmp/userspace-fips
    and bind-mounting this file as /proc/sys/crypto/fips_enabled
    
    The security context needs to be properly set otherwise
    /proc/sys/crypto/fips_enabled inherits the security context
    unconfined_u:object_r:user_tmp_t:s0 and cannot be read,
    resulting in the test seeing fips_mode=false.
    
    Fixes: https://pagure.io/freeipa/issue/8868
    Signed-off-by: Florence Blanc-Renaud <flo@redhat.com>
    Reviewed-By: Rob Crittenden <rcritten@redhat.com>