Code cleanup: **error may be null as per coding standards in 'Creating and Returning NSError Objects' (found with Analyzer)

Code/ObjectMapping/RKObjectLoader.m

@@ -153,7 +153,7 @@
         RKLogError(@"Encountered errors during mapping: %@", [[mapper.errors valueForKey:@"localizedDescription"] componentsJoinedByString:@", "]);
         
         // TODO: Construct a composite error that wraps up all the other errors
-        *error = [mapper.errors lastObject];
+        if (error) *error = [mapper.errors lastObject];   
         return nil;
     }
     

Code/Support/Parsers/JSON/RKJSONParserSBJSON.m

@@ -16,7 +16,7 @@
 	SBJsonParser* parser = [[SBJsonParser alloc] init];
 	id result = [parser objectWithString:string];
 	if (nil == result) {
-        *error = [[parser errorTrace] lastObject];
+        if (error) *error = [[parser errorTrace] lastObject];
 	}
 	[parser release];
 	
@@ -27,7 +27,7 @@
     SBJsonWriter *jsonWriter = [SBJsonWriter new];    
     NSString *json = [jsonWriter stringWithObject:self];
     if (!json) {
-        *error = [[jsonWriter errorTrace] lastObject];
+        if (error) *error = [[jsonWriter errorTrace] lastObject];
     }
     [jsonWriter release];
     return json;