sstate.bbclass: fix detection of owners matching sstate files

* without this patch:
  Python 2.7.3
  >>> sstate_search_cmd = "grep -rl /OE/jansa-test/shr-core/tmp-eglibc/pkgdata/armv7a-vfp-neon-oe-linux-gnueabi/runtime-reverse/vim-common /OE/jansa-test/shr-core/tmp-eglibc/sstate-control --exclude=master.list | sed -e 's:^.*/::' -e 's:\.populate-sysroot::'"
  >>> cmd_array = sstate_search_cmd.split(' ')
  >>> search_output = subprocess.Popen(cmd_array, stdout=subprocess.PIPE).communicate()[0]
  grep: |: No such file or directory
  grep: sed: No such file or directory

* Adding shell=True and using cmd string instead of array makes it work:
  >>> search_output = subprocess.Popen(sstate_search_cmd, shell=True, stdout=subprocess.PIPE).communicate()[0]
  >>> print search_output
  manifest-armv7a-vfp-neon-gvim.package
  manifest-armv7a-vfp-neon-vim-tiny.package
  manifest-armv7a-vfp-neon-vim.package

  But still isn't 100% reliable, I guess it's caused by some other package
  being removed from sstate while grep is already running.
  So sometimes grep can show error on STDERR
  >>> search_output = subprocess.Popen(sstate_search_cmd, shell=True, stdout=subprocess.PIPE).communicate()[0]
  grep: /OE/jansa-test/shr-core/tmp-eglibc/sstate-control/manifest-armv7a-vfp-neon-systemtap.package: No such file or directory

Signed-off-by: Martin Jansa <Martin.Jansa@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

0 files changed, 0 insertions, 0 deletions