Fix non-literal NSString format specifiers.

Trying to get things to compile on clang 4.

It seems like there was an unnecessary level of indirection on these,
but that may have been intentional. Will ask.

app/ViBundle.m

@@ -304,8 +304,8 @@ + (void)setupEnvironment:(NSMutableDictionary *)env
 
 		NSMutableString *urls = [NSMutableString string];
 		for (url in selectedURLs) {
-			[urls appendFormat:[NSString stringWithFormat:@"'%@' ",
-			    [[url absoluteString] stringByReplacingOccurrencesOfString:@"'" withString:@"'\\''"]]];
+			[urls appendFormat:@"'%@' ",
+			    [[url absoluteString] stringByReplacingOccurrencesOfString:@"'" withString:@"'\\''"]];
 		}
 		[env setObject:[urls stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] forKey:@"TM_SELECTED_URLS"];
 
@@ -316,8 +316,8 @@ + (void)setupEnvironment:(NSMutableDictionary *)env
 		if ([url isFileURL]) {
 			NSMutableString *paths = [NSMutableString string];
 			for (url in selectedURLs) {
-				[paths appendFormat:[NSString stringWithFormat:@"'%@' ",
-				    [[url path] stringByReplacingOccurrencesOfString:@"'" withString:@"'\\''"]]];
+				[paths appendFormat:@"'%@' ",
+				    [[url path] stringByReplacingOccurrencesOfString:@"'" withString:@"'\\''"]];
 			}
 			[env setObject:[paths stringByTrimmingCharactersInSet:[NSCharacterSet whitespaceCharacterSet]] forKey:@"TM_SELECTED_FILES"];