archiver.bbclass: fix the remove error

archiver.bbclass: fix the remove error

* The "tar-package" is used for saving the "Source" list for rpmbuild,
  there is no such a file when "ARCHIVER_MODE[type] ?= srpm", and there
  would be errors, it hadn't happen before was becuase that the remove
  function didn't work. Let the "rpmbuild --rmsource" to remove the
  Sources, and the remove function will just remove the tar-package file.

* Remove several unwanted "try ... exception" sentences, let the error
  raise rather than ignore them when the error happens.

* Remove several un-needed code.

[YOCTO #2619]

(From OE-Core rev: 6ac3e8be0307ecaea5e92f8bda94f1cd2193a47a)

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