Throughout avoid having to initialize constant UNICODE_STRINGs.

	Throughout avoid having to initialize constant UNICODE_STRINGs.
	* globals.cc: Define constant UNICODE_STRINGs and store in .rdata
	section.
	* fhandler_disk_file.cc: Throughout, use readonly UNICODE_STRINGs
	rather then initializing local UNICODE_STRING variable where
	applicable.
	* fhandler_mem.cc (fhandler_dev_mem::open): Ditto.
	* flock.cc (inode_t::inode_t): Ditto.
	* mmap.cc: Ditto.
	* syscalls.cc: Ditto.
	* mount.cc (fs_info::update): Ditto.
	* path.cc: Ditto.

	* ntdll.h (RtlEqualUnicodePathPrefix): Redefine to take prefix as
	UNICODE_STRING.
	(RtlEqualUnicodePathSuffix): Redefine to take suffix as UNICODE_STRING.
	* fhandler_disk_file.cc: Accommodate throughout.
	* mount.cc (fs_info::update): Ditto.
	* path.cc (cwdstuff::set): Ditto.
	* syscalls.cc: Ditto.