PM / OPP / clk: Remove unnecessary OOM message

This patch reduces the kernel size by removing error messages that duplicate
the normal OOM message.

A simplified version of the semantic patch that finds this problem is as
follows: (http://coccinelle.lip6.fr)

@@
identifier f,print,l;
expression e;
constant char[] c;
@@

e = \(kzalloc\|kmalloc\|devm_kzalloc\|devm_kmalloc\)(...);
if (e == NULL) {
  <+...
-  print(...,c,...);
  ... when any
(
  goto l;
|
  return ...;
)
  ...+> }

Signed-off-by: Quentin Lambert <lambert.quentin@gmail.com>
Acked-by: Nishanth Menon <nm@ti.com>
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

drivers/base/power/clock_ops.c

@@ -81,10 +81,8 @@ static int __pm_clk_add(struct device *dev, const char *con_id,
 		return -EINVAL;
 
 	ce = kzalloc(sizeof(*ce), GFP_KERNEL);
-	if (!ce) {
-		dev_err(dev, "Not enough memory for clock entry.\n");
+	if (!ce)
 		return -ENOMEM;
-	}
 
 	if (con_id) {
 		ce->con_id = kstrdup(con_id, GFP_KERNEL);