fdisk: inform on 'p' about wiped partitions

fdisk: inform on 'p' about wiped partitions

The wipe operation is potentially dangerous. Let's inform about it
always by 'p' (list) command to make sure user knowns about it.

	Command (m for help): p
	...
	Device     Boot Start    End Sectors Size Id Type
	/dev/sdc1        2048 204799  202752  99M 83 Linux

	Filesystem/RAID signature on partition 1 will be wiped.

Addresses: https://github.com/karelzak/util-linux/issues/437
Signed-off-by: Karel Zak <kzak@redhat.com>