[PATCH] jsm: use dynamic major number allocation

The jsm driver uses a static number of 253.  The major number 253 is a
reserved for "LOCAL/EXPERIMENTAL USE" by both char and block devices.  So
take advantage of the dynamic allocation of major number by the kernel.

Signed-off-by: V. Ananda Krishnan <mansarov@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>