zdtm: fix sigpending to check blocked signal masks

Here are a few bugs which hide each other.
* memcmp(&newset, &oldset, sizeof(newset) returns 0 is masks are equal.
* sigprocmask return sigset_t and it contains extra bits for the future,
so we need to initialize all this bits otherwise they will contain
random data.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
zdtm.sh: use tmpfs for dump files

It's optional. It's going to be used in jenkins.

time bash -x test//zdtm.sh  static/maps04
real	0m40.220s
user	0m0.096s
sys	0m12.822s

time bash -x test//zdtm.sh -t static/maps04
real	0m9.904s
user	0m0.074s
sys	0m1.630s

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
zdtm.sh: save archive with dump files

An archive is saved in unsuccessful case.

Signed-off-by: Andrey Vagin <avagin@openvz.org>
Signed-off-by: Pavel Emelyanov <xemul@parallels.com>