PM: clock_ops: fix missing clk_prepare() return value check

clk_prepare() can fail, so check its status and if it fails,
issue an error message and change the clock_entry_status to
PCE_STATUS_ERROR.
Signed-off-by: Aditya Pakki <pakki001@umn.edu>
[ rjw: Subject ]
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/power/clock_ops.c

@@ -65,10 +65,15 @@ static void pm_clk_acquire(struct device *dev, struct pm_clock_entry *ce)
 	if (IS_ERR(ce->clk)) {
 		ce->status = PCE_STATUS_ERROR;
 	} else {
-		clk_prepare(ce->clk);
-		ce->status = PCE_STATUS_ACQUIRED;
-		dev_dbg(dev, "Clock %pC con_id %s managed by runtime PM.\n",
-			ce->clk, ce->con_id);
+		if (clk_prepare(ce->clk)) {
+			ce->status = PCE_STATUS_ERROR;
+			dev_err(dev, "clk_prepare() failed\n");
+		} else {
+			ce->status = PCE_STATUS_ACQUIRED;
+			dev_dbg(dev,
+				"Clock %pC con_id %s managed by runtime PM.\n",
+				ce->clk, ce->con_id);
+		}
 	}
 }