cros_workon: allow a stop on a dead package
cros_workon: allow a stop on a dead package

Previously, you could not stop working on a package if its ebuild had
been removed. This fixes this issue by skipping canonicalization if the
package name exactly matches a name in the workon file.

BUG=11214
TEST=See below.

(cros-chroot) msb@msb ~/trunk/src/scripts $ ./cros_workon --board x86-generic list
sys-kernel/chromeos-kernel
(cros-chroot) msb@msb ~/trunk/src/scripts $ echo "=foo/bar-9999" >> ~/trunk/.config/cros_workon/x86-generic
(cros-chroot) msb@msb ~/trunk/src/scripts $ ./cros_workon --board x86-generic list
sys-kernel/chromeos-kernel
foo/bar
(cros-chroot) msb@msb ~/trunk/src/scripts $ ./cros_workon --board x86-generic stop foo/bar
!!! No packages matching 'foo/bar'
WARNING: error looking up package foo/bar
ERROR  : Error parsing package list

*** I made changes to cros_workon here

(cros-chroot) msb@msb ~/trunk/src/scripts $ ./cros_workon --board x86-generic list
sys-kernel/chromeos-kernel
foo/bar
(cros-chroot) msb@msb ~/trunk/src/scripts $ ./cros_workon --board x86-generic stop foo/bar
INFO   : Stopped working on 'foo/bar' for 'x86-generic'
(cros-chroot) msb@msb ~/trunk/src/scripts $ ./cros_workon --board x86-generic list
sys-kernel/chromeos-kernel

Change-Id: Id5cbd2b145b4d0fca96cfb245f1ac99e0b3cbdf3

Review URL: http://codereview.chromium.org/6379006

crawford/scripts,coreos/scripts,marineam/coreos-scripts,crawford/scripts,zhang0137/scripts,marineam/coreos-scripts,nicescale/scripts,BugRoger/scripts,fivethreeo/scripts,sigma/coreos-scripts,crawford/scripts,mjg59/scripts,gtank/scripts,marineam/coreos-scripts,andrejro/coreos--scripts,bcwaldon/coreos-scripts,mischief/scripts,trnubo/scripts,trnubo/scripts,vmware/coreos-scripts,vmware/coreos-scripts,zhang0137/scripts,bcwaldon/coreos-scripts,trnubo/scripts,sigma/coreos-scripts,endocode/scripts,fivethreeo/scripts,BugRoger/scripts,nicescale/scripts,nicescale/scripts,gtank/scripts,glevand/coreos--scripts,vmware/coreos-scripts,mischief/scripts,sigma/coreos-scripts,smilart/scripts,mjg59/scripts,glevand/coreos--scripts,mjg59/scripts,andrejro/coreos--scripts,BugRoger/scripts,fivethreeo/scripts,mischief/scripts,gtank/scripts,zhang0137/scripts,coreos/scripts,andrejro/coreos--scripts,smilart/scripts,smilart/scripts,bcwaldon/coreos-scripts,endocode/scripts,endocode/scripts