Minor Makefile fixes

[Mike Hommey]

On Mon, May 14, 2007 at 12:36:36PM -0400, Adam Jackson <ajackson at redhat.com> wrote:
> Attached patch from Fedora CVS does two things:
> 
> - 'mkdir -p' on the install directory, for the case where $DESTDIR is an
> empty install root.

"install -d" should be used instead.

> - Set CFLAGS with ?=, not =, so the environment can override it.

Actually this is not needed. If you run "make CFLAGS=something" CFLAGS
will be overriden if it is set with =.

Mike