[PATCH] tpm: fix bug introduced by the /proc/misc

In fixing the /proc/misc problem that was reported last week where the tpm
module name was being obfuscated in /proc/misc I introduced a bug in the
module unloading code.  This patch fixes the problem.

Signed-off-by: Kylene Hall <kjhall@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>