syntax-check.mk: Drop needless _src2 variable
syntax-check.mk: Drop needless _src2 variable

The aim was to break a long line, but it is not long anymore.

Signed-off-by: Michal Privoznik <83d82aaba2eed257f4814b0c239c260c4caaadf0@redhat.com>

nertpinx/libvirt,jardasgit/libvirt,zippy2/libvirt,jardasgit/libvirt,libvirt/libvirt,jfehlig/libvirt,zippy2/libvirt,libvirt/libvirt,libvirt/libvirt,jardasgit/libvirt,libvirt/libvirt,olafhering/libvirt,nertpinx/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,fabianfreyer/libvirt,crobinso/libvirt,zippy2/libvirt,fabianfreyer/libvirt,olafhering/libvirt,crobinso/libvirt,jardasgit/libvirt,jfehlig/libvirt,nertpinx/libvirt,olafhering/libvirt,nertpinx/libvirt,olafhering/libvirt,crobinso/libvirt,crobinso/libvirt,jfehlig/libvirt,zippy2/libvirt,nertpinx/libvirt,jardasgit/libvirt,jfehlig/libvirt