Fix typo in include guard, found by clang 3.4.

MFC after:	3 days
Initialize variable in sys/x86/iommu/busdma_dmar.c, to avoid possible
uninitialized use.

Reviewed by:	kib
Remove generate-release.sh from head/.

The release.sh (based heavily on generate-release.sh) has been
used for the 9.2-RELEASE and 10.0-RELEASE cycles, so make sure
there is no confusion on what is currently being used by having
two similar scripts.

A big "thank you" to Nathan Whitehorn, the author of the
generate-release.sh script, for writing this utility.

No objection:	nwhitehorn
MFC after:	never
Sponsored by:	The FreeBSD Foundation