On systems with block devices containing a slash (virtual dasd, cciss,
etc), reiserfs will fail to initialize /proc/fs/reiserfs/<dev> due to it
being interpreted as a subdirectory.  The generic block device code changes
the / to !  for use in the sysfs tree.  This patch uses that convention.

Tested by making dm devices use dm/<number> rather than dm-<number>

[akpm@osdl.org: name variables consistently]
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>