[binutils-gdb] Skip catch-syscall.exp on HP-UX target

[sergiodj+buildbot@redhat.com]

*** TEST RESULTS FOR COMMIT 5d0962b2e982eb8210df40cc23f5a47d0339e789 ***

Author: Yao Qi <yao.qi@linaro.org>
Branch: master
Commit: 5d0962b2e982eb8210df40cc23f5a47d0339e789

Skip catch-syscall.exp on HP-UX target
"catch syscall" doesn't work on HP-UX.

gdb/testsuite:

2015-03-11  Yao Qi  <yao.qi@linaro.org>

	* gdb.base/catch-syscall.exp: Skip it on HP-UX target.