quoted source_path/VERSION in `cut` command in case of paths with quotes

When I tried to run ./configure on a Windows 8.1 machine with msysGit, it failed with the error "cut: /c/Program: No such file or directory\
cut: Archives/Programs/qemu/VERSION: No such file or directory". I determined it was because the call to `cut` in this file wasn't built for spaces, so I quoted it and here we are.
I have not tested it with any other OS, but it should work on other Windows versions, the latest Mac OS X and the main Linuxes.