[PATCH] sysfs error handling fix

Patch from: Rusty Lynch <rusty@linux.co.intel.com>

Attempting to cat a sysfs file that returns an error will result in an
endless dump of garbage to the screen because the result of the specific show
operation was being saved to a size_t (unsigned) and then later checked for a
negative value.

Here is a trivial patch to fix the error.

fs/sysfs/inode.c

@@ -210,7 +210,7 @@ static int fill_read_buffer(struct file * file, struct sysfs_buffer * buffer)
 	struct kobject * kobj = file->f_dentry->d_parent->d_fsdata;
 	struct sysfs_ops * ops = buffer->ops;
 	int ret = 0;
-	size_t count;
+	ssize_t count;
 
 	if (!buffer->page)
 		buffer->page = (char *) __get_free_page(GFP_KERNEL);