bitbake: cooker: convert type which needs to be marshalled

We assume that the value taken by variable v can be string,
integer or any type which can be marshalled by xmlrpc. This
change would help us to convert the non marshallable types
to string. So that we don't get exception from xmlrpc.

[YOCTO #10740]

(Bitbake rev: efb0e47479b3526bc047112f7200087c5844bba4)

Signed-off-by: Sujith H <sujith.h@gmail.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cooker.py

@@ -1488,7 +1488,7 @@ class BBCooker:
                 v = self.data.getVar(k, expand)
                 if not k.startswith("__") and not isinstance(v, bb.data_smart.DataSmart):
                     dump[k] = {
-    'v' : v ,
+    'v' : str(v) ,
     'history' : self.data.varhistory.variable(k),
                     }
                     for d in flaglist: