kbuild: append git revision for all untagged commits

adds revision suffix for untagged commits that are reachable from a tag

I'm bisecting and don't get the -g...... suffix.  The reason is, that

	git name-rev --tags HEAD

returns e.g.

	HEAD tags/v2.6.17-rc1^0~1067

which is currently good enough for setlocalversion to skip the suffix.
This introduces a dependecy to grep -E, which should be fine.
Signed-off-by: NUwe Zeisberger <zeisberg@informatik.uni-freiburg.de>
Acked-By: NRyan Anderson <ryan@michonline.com>
Signed-off-by: NSam Ravnborg <sam@ravnborg.org>

scripts/setlocalversion

@@ -11,7 +11,7 @@ cd "${1:-.}" || usage
 # Check for git and a git repo.
 if head=`git rev-parse --verify HEAD 2>/dev/null`; then
 	# Do we have an untagged version?
-	if  [ "`git name-rev --tags HEAD`" = "HEAD undefined" ]; then
+	if git name-rev --tags HEAD | grep -E '^HEAD[[:space:]]+(.*~[0-9]*|undefined)$' > /dev/null; then
 		printf '%s%s' -g `echo "$head" | cut -c1-8`
 	fi