ci: Move source directory under $(CI_USER_HOME)

Now that we have a home directory for the user, storing the
source there rather than in a custom top-level directory is
the obvious choice.

Later on we're also going to add some more files related to
builds, and storing everything in the user's home directory
will keep things nice and tidy.
Signed-off-by: NAndrea Bolognani <abologna@redhat.com>
Reviewed-by: NJán Tomko <jtomko@redhat.com>

ci/Makefile

@@ -18,7 +18,7 @@ CI_HOST_SRCDIR = $(CI_SCRATCHDIR)/src
 # The directory holding the source inside the
 # container, i.e. where we want to expose
 # the $(CI_HOST_SRCDIR) directory from the host
-CI_CONT_SRCDIR = /src
+CI_CONT_SRCDIR = $(CI_USER_HOME)/libvirt
 
 # Relative directory to perform the build in. This
 # defaults to using a separate build dir, but can be