clocksource: Fix 'ret' data type of sysfs_override_clocksource() and sysfs_unbind_clocksource()

sysfs_override_clocksource(): The expression 'if (ret >= 0)' is always true.
This will cause clocksource_select() to always run.
Thus modified ret to be of type ssize_t.

sysfs_unbind_clocksource(): The expression 'if (ret < 0)' is always false.
So in case sysfs_get_uname() failed, the expression won't take an effect.
Thus modified ret to be of type ssize_t.

Signed-off-by: Elad Wexler <elad.wexler@gmail.com>
Signed-off-by: John Stultz <john.stultz@linaro.org>
diff --git a/kernel/time/clocksource.c b/kernel/time/clocksource.c
index 64cf63c..c9317e1 100644
--- a/kernel/time/clocksource.c
+++ b/kernel/time/clocksource.c
@@ -940,7 +940,7 @@
 					  struct device_attribute *attr,
 					  const char *buf, size_t count)
 {
-	size_t ret;
+	ssize_t ret;
 
 	mutex_lock(&clocksource_mutex);
 
@@ -968,7 +968,7 @@
 {
 	struct clocksource *cs;
 	char name[CS_NAME_LEN];
-	size_t ret;
+	ssize_t ret;
 
 	ret = sysfs_get_uname(buf, name, count);
 	if (ret < 0)