python: Fix problems of virDomain{Set, Get}BlockIoTune bindings

The parameter 'params' is useless for virDomainGetBlockIoTune API,
and the return value type should be a virTypedParameterPtr but not
integer. And "PyArg_ParseTuple" in functions
libvirt_virDomain{Set,Get}BlockIoTune misses format unit for "format"
argument.

* libvirt-override-api.xml: Remove useless the parameter 'params'
from virDomainGetBlockIoTune API, and change return value type from
integer to virTypedParameterPtr.

* python/libvirt-override.c: Add the missed format units.

RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=770683Signed-off-by: NAlex Jia <ajia@redhat.com>

python/libvirt-override-api.xml

@@ -401,9 +401,8 @@
       <info>Get the I/O tunables for a block device</info>
       <arg name='dom' type='virDomainPtr' info='pointer to the domain'/>
       <arg name='disk' type='const char *' info='disk name'/>
-      <arg name='params' type='virTypedParameterPtr' info='Pointer to blkio tuning params object'/>
       <arg name='flags' type='unsigned int' info='an OR&apos;ed set of virDomainModificationImpact'/>
-      <return type='int' info='0 in case of success, -1 in case of failure'/>
+      <return type='virTypedParameterPtr' info='the I/O tunables value or None in case of error'/>
     </function>
     <function name='virDomainBlockPeek' file='python'>
       <info>Read the contents of domain's disk device</info>

python/libvirt-override.c

@@ -3301,7 +3301,7 @@ libvirt_virDomainSetBlockIoTune(PyObject *self ATTRIBUTE_UNUSED,
     int nparams = 0, i;
     int c_ret;
 
-    if (!PyArg_ParseTuple(args, (char *)"Ozi:virDomainSetBlockIoTune",
+    if (!PyArg_ParseTuple(args, (char *)"OzOi:virDomainSetBlockIoTune",
                           &pyobj_domain, &disk, &pyinfo, &flags))
         return(NULL);
     domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);
@@ -3395,7 +3395,7 @@ libvirt_virDomainGetBlockIoTune(PyObject *self ATTRIBUTE_UNUSED,
     virTypedParameterPtr params;
     int c_ret;
 
-    if (!PyArg_ParseTuple(args, (char *)"Oi:virDomainGetBlockIoTune",
+    if (!PyArg_ParseTuple(args, (char *)"Ozi:virDomainGetBlockIoTune",
                           &pyobj_domain, &disk, &flags))
         return(NULL);
     domain = (virDomainPtr) PyvirDomain_Get(pyobj_domain);