[PATCH] sn2: use static ->proc_fops

fix-rmmod-read-write-races-in-proc-entries.patch doesn't want dynamically
allocated ->proc_fops, because it will set it to NULL at module unload time.

Regardless of module status, switch to statically allocated ->proc_fops which
leads to simpler code without wrappers.

AFAICS, also fix the following bug: "sn_force_interrupt" proc entry set
->write for itself, but was created with 0444 permissions. Change to 0644.

Signed-off-by: Alexey Dobriyan <adobriyan@openvz.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: "Eric W. Biederman" <ebiederm@xmission.com>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>