Don't use --force in gzip decompress

Normally gzip stops reading input when it has reached its own end-of
input marker even when that is before the end of input. This is
overridden by --force for decompression and it is creating a problem for
us because suspend images on disk are represented as devices that are
larger than the actual content - so --force kept reading beyond the
actual input and this in turn was not accepted by the code taking the
uncompressed output.

Signed-off-by: Christian Lindig <christian.lindig@citrix.com>

ocaml/libs/xapi-compression/xapi_compression.ml

@@ -44,7 +44,11 @@ module Make (Algorithm : ALGORITHM) = struct
  let open Safe_resources in
  Unixfd.with_pipe ~loc:__LOC__ () @@ fun zcat_out zcat_in ->
  let args =
- if mode = Compress then [] else ["--decompress"] @ ["--stdout"; "--force"]
+ match mode with
+ | Compress ->
+ []
+ | Decompress ->
+ ["--decompress"; "--stdout"]
  in
  let stdin, stdout, close_now, close_later =
  match input with