libsensors: Differentiate between different read error types.

git-svn-id: http://lm-sensors.org/svn/lm-sensors/branches/lm-sensors-3.0.0@4896 7894878c-1315-0410-8ee3-d5d059ff63e0

CHANGES

@@ -4,6 +4,7 @@ lm-sensors CHANGES file
 SVN
   Makefile: Add sensors-conf-convert to make install
   libsensors: Notify the caller when writing a value fails
+              Differentiate between different read error types
   sensord: Log the error code on failure
   sensors: Fix spurious critical temperature alarm
   sensors-conf-convert: Add a short help text

lib/sysfs.c

@@ -558,9 +558,8 @@ int sensors_read_sysfs_attr(const sensors_chip_name *name,
 	snprintf(n, NAME_MAX, "%s/%s", name->path, subfeature->name);
 	if ((f = fopen(n, "r"))) {
 		int res = fscanf(f, "%lf", value);
-		fclose(f);
-		if (res != 1)
-			return -SENSORS_ERR_KERNEL;
+		if (fclose(f) || res != 1)
+			return -SENSORS_ERR_ACCESS_R;
 		*value /= get_type_scaling(subfeature->type);
 	} else
 		return -SENSORS_ERR_KERNEL;