[POWERPC] Fix rtas_flash procfs interface

Handling of the proc_dir_entry->count was changed in 2.6.24-rc5.
After this change, the default value for pde->count is 1 and not 0 as
before.  Therefore, if we want to check whether our procfs file is
already opened (already in use), we have to check if pde->count is
greater than 2 rather than 1.

Signed-off-by: Maxim Shchetynin <maxim@de.ibm.com>
Signed-off-by: Jens Osterkamp <jens@de.ibm.com>
Signed-off-by: Paul Mackerras <paulus@samba.org>