[PATCH] kbuild: fix make clean damaging hg repos

Running 'make clean' was quietly deleting files in Mercurial kernel
repositories matching '.*.d', which was corrupting the tags portions of the
repository.  Spotted and fixed by several people.

Signed-off-by: Matt Mackall <mpm@selenic.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>