microblaze: Fix return value for sys_ipc

Signed-off-by: John Linn <john.linn@xilinx.com>
Signed-off-by: Michal Simek <monstr@monstr.eu>

arch/microblaze/kernel/sys_microblaze.c

@@ -131,7 +131,7 @@ sys_ipc(uint call, int first, int second, int third, void *ptr, long fifth)
 		ret = sys_shmctl(first, second, (struct shmid_ds *) ptr);
 		break;
 	}
-	return -EINVAL;
+	return ret;
 }
 
 asmlinkage int sys_vfork(struct pt_regs *regs)