patchtest: ignore patch file metadata from SRC_URI

patchtest: ignore patch file metadata from SRC_URI

The test_src_uri_left_files check prepares a list of patchfiles SRC_URI from
before and after the patch is applied, looking for dangling patches.

The name of the files in this list can be incorrect, in case the URI contains
some extra metadata (like patchdir), because os.path.basename will use the last portion
of the line being processed, which is independent from the files in question.

To avoid this, try to use only the first portion of URI, before any extra metadata.

Signed-off-by: Gyorgy Sarvari <skandigraun@gmail.com>
Signed-off-by: Mathieu Dubois-Briand <mathieu.dubois-briand@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>