[PATCH] Ensure that 'make distclean' does not delete files in '.git'

Currently, 'make distclean' causes stgit to barf since it may delete
files in .git/patches.  We really shouldn't allow 'make distclean'
anywhere near .git...

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>