HOB: 'str' object has no attribute 'close'

HOB: 'str' object has no attribute 'close'

For builddetailspage.py:
  The "f" was a stream in the past, it is a string now, so it doesn't
  need f.close(), and change its name to "branch".

  And we don't need the "2>&1" since bb.process.run() can handle it, it
  will raise exception when error occurs, we should handle the exception
  ourselves if we want to ignore the error.

For hig.py:
  Use bb.process.Popen() since it doesn't need the return value. If we
  use bb.process.run(), the parent process will wait for the child process
  to terminate to get the result.

[YOCTO #2511]

(Bitbake rev: ab10f3da1976581c371c43cdb88f405cf6fbcd95)

Signed-off-by: Robert Yang <liezhi.yang@windriver.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>