spapr: Remove NULL checks on error_propagate() calls

Patch created mechanically by rerunning:

  $  spatch --sp-file scripts/coccinelle/error_propagate_null.cocci \
	    --macro-file scripts/cocci-macro-file.h \
	    --dir . --in-place
Signed-off-by: NMarkus Armbruster <armbru@redhat.com>
Message-Id: <20190318190148.18283-1-armbru@redhat.com>
Signed-off-by: NDavid Gibson <david@gibson.dropbear.id.au>

hw/ppc/spapr_pci.c

@@ -1488,9 +1488,7 @@ static void spapr_pci_plug(HotplugHandler *plug_handler,
     }
 
 out:
-    if (local_err) {
-        error_propagate(errp, local_err);
-    }
+    error_propagate(errp, local_err);
 }
 
 static void spapr_pci_unplug(HotplugHandler *plug_handler,