pstore: skip zero size persistent ram buffer in traverse
pstore: skip zero size persistent ram buffer in traverse

In ramoops_pstore_read, a valid prz pointer with zero size buffer will
break traverse of all persistent ram buffers.  The latter buffer might be
lost.

Signed-off-by: Liu ShuoX <df7da900ca6d4d8dc52d8adb26aa75aef11ea28b@intel.com>
Cc: "Zhang, Yanmin" <232a135a0093779c691103f08ca7218045d46eb9@linux.intel.com>
Cc: Colin Cross <380081620a7947c89c11153c5513f34019caa923@android.com>
Reviewed-by: Kees Cook <50cb10d2be062154b17ab4d66a4eab34f1cf1c84@chromium.org>
Signed-off-by: Andrew Morton <5c1e68b099950c134891f0b6e179498a8ebe9cf9@linux-foundation.org>
Signed-off-by: Tony Luck <e7984595ec0368ff920a7b3521dc7093683f6f26@intel.com>

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