[IA64] arch/ia64/sn/kernel/mca.c: undo lock when sn_oemdata can't be extended

Clean up locking state in failure path.

Signed-off-by: Roel Kluin <12o3l@tiscali.nl>
Cc: Jes Sorensen <jes@trained-monkey.org>
Cc: "Luck, Tony" <tony.luck@intel.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Tony Luck <tony.luck@intel.com>
diff --git a/arch/ia64/sn/kernel/mca.c b/arch/ia64/sn/kernel/mca.c
index 3db62f2..868c9aa 100644
--- a/arch/ia64/sn/kernel/mca.c
+++ b/arch/ia64/sn/kernel/mca.c
@@ -98,6 +98,7 @@
 	while (*sn_oemdata_size > sn_oemdata_bufsize) {
 		u8 *newbuf = vmalloc(*sn_oemdata_size);
 		if (!newbuf) {
+			mutex_unlock(&sn_oemdata_mutex);
 			printk(KERN_ERR "%s: unable to extend sn_oemdata\n",
 			       __FUNCTION__);
 			return 1;