pstore: fix one type of return value in pstore

the return type of function _read_ in pstore is size_t,
but in the callback function of _read_, the logic doesn't
consider it too much, which means if negative value (assuming
error here) is returned, it will be converted to positive because
of type casting. ssize_t is enough for this function.

Signed-off-by: Chen Gong <gong.chen@linux.intel.com>
Signed-off-by: Tony Luck <tony.luck@intel.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/include/linux/pstore.h b/include/linux/pstore.h
index 41977737bb7d..14ce2f5d08af 100644
--- a/include/linux/pstore.h
+++ b/include/linux/pstore.h
@@ -35,7 +35,7 @@ struct pstore_info {
         struct mutex    buf_mutex;      /* serialize access to 'buf' */
         char            *buf;
         size_t          bufsize;
-        size_t          (*read)(u64 *id, enum pstore_type_id *type,
+        ssize_t         (*read)(u64 *id, enum pstore_type_id *type,
                         struct timespec *time);
         u64             (*write)(enum pstore_type_id type, size_t size);
         int             (*erase)(u64 id);