PM / clock_ops: check return of clk_enable() in pm_clk_resume()

The clk_enable() call in the pm_clk_resume() call returns an error
that is not being checked. If clk_enable() fails then we should
not set the state of the clock to PCE_STATUS_ENABLED.

Note, the issue of warning the user if this fails has not been
addressed in this patch as this is not the only place the driver
calls clk_enable().

Signed-off-by: Ben Dooks <ben.dooks@codethink.co.uk>
Reviewed-by: Ian Molton <ian.molton@codethink.co.uk>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>
diff --git a/drivers/base/power/clock_ops.c b/drivers/base/power/clock_ops.c
index b9dd8fa..cad7190 100644
--- a/drivers/base/power/clock_ops.c
+++ b/drivers/base/power/clock_ops.c
@@ -252,6 +252,7 @@
 	struct pm_subsys_data *psd = dev_to_psd(dev);
 	struct pm_clock_entry *ce;
 	unsigned long flags;
+	int ret;
 
 	dev_dbg(dev, "%s()\n", __func__);
 
@@ -262,8 +263,9 @@
 
 	list_for_each_entry(ce, &psd->clock_list, node) {
 		if (ce->status < PCE_STATUS_ERROR) {
-			clk_enable(ce->clk);
-			ce->status = PCE_STATUS_ENABLED;
+			ret = clk_enable(ce->clk);
+			if (!ret)
+				ce->status = PCE_STATUS_ENABLED;
 		}
 	}