powerpc/pseries: Correct string length in pseries_of_derive_parent()
powerpc/pseries: Correct string length in pseries_of_derive_parent()

Commit a030e1e4bbd085bbcfd0a23f8d355fcd41f39bed make a change to use
kstrndup() instead of kmalloc() + strlcpy() in the pseries_of_derive_parent()
routine that introduces a subtle change in the parent path name generated.
The kstrndup() routine will copy n characters followed by a terminating null,
whereas strlcpy() will copy n-1 characters and add a terminating null.

This slight difference results in having a parent path that includes the
tailing '/' character, "/cpus/" vs. "/cpus". This then causes the subsequent
call to of_find_node_by_path() to fail, and in the case of DLPAR add
operations the DLPAR request fails.

This patch decrements the pointer returned from kbasename() to point to the
'/' character before the base name instead of the base name. This then
adjusts the string length calculations to not include the trailing '/'
in the parent path name.

Signed-off-by: Nathan Fontenot <4b7bfe500077bf77c5456931a34b0b70e36e0bc6@linux.vnet.ibm.com>
Reviewed-by: Andy Shevchenko <74f0c009df510614346aa771cd21959b78cdb413@linux.intel.com>
Signed-off-by: Michael Ellerman <864f124608374e06e4da1fa5d2e47ed839b95411@ellerman.id.au>

KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs,KristFoundation/Programs