Fix some warnings in ObjC code.

webrtc/api/objc/RTCIceCandidate.mm

Index: webrtc/api/objc/RTCIceCandidate.mm
diff --git a/webrtc/api/objc/RTCIceCandidate.mm b/webrtc/api/objc/RTCIceCandidate.mm
index b0b8abc8ca1d2409eb13596c84bf8c3846f24d09..ecc128f8b291074404af58380fe7e5698b444115 100644
--- a/webrtc/api/objc/RTCIceCandidate.mm
+++ b/webrtc/api/objc/RTCIceCandidate.mm
@@ -21,7 +21,7 @@
 @synthesize sdp = _sdp;
 
 - (instancetype)initWithSdp:(NSString *)sdp
-              sdpMLineIndex:(NSInteger)sdpMLineIndex
+              sdpMLineIndex:(int)sdpMLineIndex
                      sdpMid:(NSString *)sdpMid {
   NSParameterAssert(sdp.length);
   if (self = [super init]) {
@@ -33,9 +33,9 @@
 }
 
 - (NSString *)description {
-  return [NSString stringWithFormat:@"RTCIceCandidate:\n%@\n%ld\n%@",
+  return [NSString stringWithFormat:@"RTCIceCandidate:\n%@\n%d\n%@",
                                     _sdpMid,
-                                    (long)_sdpMLineIndex,
+                                    _sdpMLineIndex,
                                     _sdp];
 }