powerpc,kvm: fix imbalance srcu_read_[un]lock()

At the point of up_out label in kvmppc_hv_setup_htab_rma(),
srcu read lock is still held.

We have to release it before return.

Signed-off-by: Lai Jiangshan <laijs@cn.fujitsu.com>
Cc: Marcelo Tosatti <mtosatti@redhat.com>
Cc: Gleb Natapov <gleb@redhat.com>
Cc: Alexander Graf <agraf@suse.de>
Cc: Benjamin Herrenschmidt <benh@kernel.crashing.org>
Cc: Paul Mackerras <paulus@samba.org>
Cc: kvm@vger.kernel.org
Cc: kvm-ppc@vger.kernel.org
Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Reviewed-by: Josh Triplett <josh@joshtriplett.org>

arch/powerpc/kvm/book3s_hv.c

@@ -1864,7 +1864,7 @@ static int kvmppc_hv_setup_htab_rma(struct kvm_vcpu *vcpu)
 
  up_out:
 	up_read(&current->mm->mmap_sem);
-	goto out;
+	goto out_srcu;
 }
 
 int kvmppc_core_init_vm(struct kvm *kvm)