tools/livepatch: Improve output

tools/livepatch: Improve output

Improving the output of xen-livepatch, which is currently hard to read,
especially when an error occurs.

Some examples of the changes:
Before:
    $ xen-livepatch apply test
    Performing apply:. completed
After:
    $ xen-livepatch apply test
    Applying test:. completed

Before:
    $ xen-livepatch apply test2
    test2 failed with 22(Invalid argument)
    Performing apply: (no newline)
After:
    $ xen-livepatch apply test2
    Applying test2: failed
    Error 22: Invalid argument

Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Wei Liu <wei.liu2@citrix.com>
Signed-off-by: Ross Lagerwall <ross.lagerwall@citrix.com>