infra: clean up 'Patching' message

The 'Patching' message in the generic infrastructure prints not only the
package name, but also a reference to the assumed package directory, based
on FOO_DIR_PREFIX/FOO_RAWNAME. This doesn't really add value, as the name
of the package is already apparent from the message and its location should
be obvious. Hence, this patch simply reduces the print to "Patching".

Signed-off-by: Thomas De Schampheleire <thomas.de.schampheleire@gmail.com>
Acked-by: Arnout Vandecappelle (Essensium/Mind) <arnout@mind.be>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>