Correct type for malloc().

Submitted by:	"Conrad Meyer" <conrad.meyer@isilon.com>
Fix pw(8) deletion of group "username" on userdel even if group "username"
is not associated with user "username". E.g., user "foo" has primary group
"wheel" and is unassociated with group "foo", yet userdel would delete the
group "foo" when deleting user "foo" (despite the fact that user "foo" is
not associated with group "foo" in any way).

Patch committed with minor style(9) changes.

PR:		bin/169471
Submitted by:	Alexander Pyhalov <apyhalov@gmail.com>
Add amd64 EFI headers

Sponsored by:	The FreeBSD Foundation