[PATCH] kbuild: version.h should depend on .kernelrelease

Rebuilding a previously built tree while using make's -j option from
time to time results in the version.h check running at the same time as
the updating of .kernelrelease, resulting in UTS_RELEASE remaining an
empty string (and as a side effect causing the entire kernel to be
rebuilt).

Signed-Off-By: Jan Beulich <jbeulich@novell.com>
Signed-off-by: Sam Ravnborg <sam@ravnborg.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>