sulogin: clean up error messages

Signed-off-by: Karel Zak <kzak@redhat.com>
chcpu: clean up error messages

Signed-off-by: Karel Zak <kzak@redhat.com>
libmount: use err.h in test

Signed-off-by: Karel Zak <kzak@redhat.com>
hwclock: use warn() to print cmos errors

Signed-off-by: Karel Zak <kzak@redhat.com>
mkfs.cramfs: use standard error message

Signed-off-by: Karel Zak <kzak@redhat.com>