ARM: cleanup: pwrdm_can_ever_lose_context() checking

pwrdm_can_ever_lose_context() is only ever called from the OMAP GPIO
code, and only with a pointer returned from omap_hwmod_get_pwrdm().
omap_hwmod_get_pwrdm() only ever returns NULL on error, so using
IS_ERR_OR_NULL() to validate the passed pointer is silly.  Use a
simpler !ptr check instead.

Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
diff --git a/arch/arm/mach-omap2/powerdomain.c b/arch/arm/mach-omap2/powerdomain.c
index dea62a9..36a6918 100644
--- a/arch/arm/mach-omap2/powerdomain.c
+++ b/arch/arm/mach-omap2/powerdomain.c
@@ -1054,7 +1054,7 @@
 {
 	int i;
 
-	if (IS_ERR_OR_NULL(pwrdm)) {
+	if (!pwrdm) {
 		pr_debug("powerdomain: %s: invalid powerdomain pointer\n",
 			 __func__);
 		return 1;