[PATCH -tip] irq: Do not attempt to create subdirectories if /proc/irq/<irq> failed

[Cyrill Gorcunov <gorcunov@openvz.org>]

If a parent directory (ie /proc/irq/<irq>) could not be created
we should not attempt to create subdirectories. Otherwise it would
lead that "smp_affinity" and "spurious" entries are may be registered
under /proc root instead of a proper place.

Signed-off-by: Cyrill Gorcunov <gorcunov@openvz.org>
---

Please review. This is not critical even if will be failing
at this point even at every call but better to be sure all
goe fine. I hope I don't miss anything?

 kernel/irq/proc.c |    2 ++
 1 file changed, 2 insertions(+)

Index: linux-2.6.git/kernel/irq/proc.c
=====================================================================
--- linux-2.6.git.orig/kernel/irq/proc.c
+++ linux-2.6.git/kernel/irq/proc.c
@@ -214,6 +214,8 @@ void register_irq_proc(unsigned int irq,
 
 	/* create /proc/irq/1234 */
 	desc->dir = proc_mkdir(name, root_irq_dir);
+	if (!desc->dir)
+		return;
 
 #ifdef CONFIG_SMP
 	/* create /proc/irq/<irq>/smp_affinity */