pimgen: use yaml.safe_load

The extended parsing features of yaml.load are not required.

Change-Id: I9517f20c291a6fa3478b13216cf1d503535dbc15
Signed-off-by: Brad Bishop <bradleyb@fuzziesquirrel.com>
diff --git a/pimgen.py b/pimgen.py
index f7710c1..0b6cb6b 100755
--- a/pimgen.py
+++ b/pimgen.py
@@ -273,7 +273,7 @@
         events = []
         for x in yaml_files:
             with open(os.path.join(events_dir, x), 'r') as fd:
-                for e in yaml.load(fd.read()).get('events', {}):
+                for e in yaml.safe_load(fd.read()).get('events', {}):
                     events.append(e)
 
         return Everything(
@@ -293,7 +293,7 @@
         interfaces = []
         for x in yaml_files:
             with open(os.path.join(interfaces_dir, x), 'r') as fd:
-                for i in yaml.load(fd.read()):
+                for i in yaml.safe_load(fd.read()):
                     interfaces.append(i)
 
         return interfaces