spec: prevent git apply from searching for the .git directory

By default, git tries to find the repository root by looking for the nearest parent directory containing a .git subdirectory. If the unpacked tarball doesn't include the .git directory, it can lead to git trying to apply the patch to the nearest parent git repository (e.g. the kernel dist-git in case of a local fedpkg prep) instead of the current directory.

Thus, pass --work-tree=. to git apply, so that it doesn't search for the .git directory outside the current directory.

This is an alternative to !2105 (closed).

Signed-off-by: Ondrej Mosnacek omosnace@redhat.com