mkswap: default to V1 in any case

mkswap: default to V1 in any case

mkswap(8) enforces to use v0 swap format when pagesize > 16kB.
(use case might be ppc64 with CONFIG_PPC_64K_PAGES).

As version 0 swap is not supported anymore by recent kernels, the
behaviour in this case is rather strange.

Here is a testcase:

for i in 4 8 16 32 64; do mkswap -p `expr $i \* 1024` ./swap.file; done
Setting up swapspace version 1, size = 4294963 kB

Using user-specified page size 8192, instead of the system values
4096/4096
Setting up swapspace version 1, size = 4294959 kB

Using user-specified page size 16384, instead of the system values
4096/4096
Setting up swapspace version 1, size = 4294950 kB

Using user-specified page size 32768, instead of the system values
4096/4096
Setting up swapspace version 0, size = 4294934 kB

Using user-specified page size 65536, instead of the system values
4096/4096
Setting up swapspace version 0, size = 4294901 kB

Signed-off-by: Matthias Koenig <mkoenig@suse.de>
Signed-off-by: Karel Zak <kzak@redhat.com>