check on repository branch shouldn't check all branches in repo

[Ian Clatworthy]

'bzr check branch-in-repo' should just check branch-in-repo, it's tree and repository, without checking all branches in the shared repository. Right now, it looks like it's doing too much, e.g.

$ bzr check
Checking working tree at '/home/ian/Projects/bzr/bzr/finish-commit-hook'.
Checking working tree at '/home/ian/Projects/bzr/bzr/2.0'.
Checking branch at 'file:///home/ian/Projects/bzr/bzr/2.0/'.
Checking branch at 'file:///home/ian/Projects/bzr/bzr/finish-commit-hook/'.
Checking working tree at '/home/ian/Projects/bzr/bzr/integration-2.0'.
Checking branch at 'file:///home/ian/Projects/bzr/bzr/integration-2.0/'.
Checking working tree at '/home/ian/Projects/bzr/bzr/pdf-chm-docs'.
Checking branch at 'file:///home/ian/Projects/bzr/bzr/pdf-chm-docs/'.
Checking working tree at '/home/ian/Projects/bzr/bzr/win32-install-for-2.0'.
Checking branch at 'file:///home/ian/Projects/bzr/bzr/win32-install-for-2.0/'.
Checking working tree at '/home/ian/Projects/bzr/bzr/win32-install-for-2.0/build-win32/bzr/release'.
Checking branch at 'file:///home/ian/Projects/bzr/bzr/win32-install-for-2.0/build-win32/bzr/release/'.
Checking working tree at '/home/ian/Projects/bzr/bzr/win32-install-for-2.0/build-win32/bzr/trunk'.
Checking branch at 'file:///home/ian/Projects/bzr/bzr/win32-install-for-2.0/build-win32/bzr/trunk/'.
Checking repository at 'file:///home/ian/Projects/bzr/bzr/'.