Log: remove the obsolete printf-style functions

src/output/plugins/FifoOutputPlugin.cxx

@@ -194,9 +194,9 @@ FifoOutput::Cancel() noexcept
 	} while (bytes > 0 && errno != EINTR);
 
 	if (bytes < 0 && errno != EAGAIN) {
-		FormatErrno(fifo_output_domain,
-			    "Flush of FIFO \"%s\" failed",
-			    path_utf8.c_str());
+		FmtError(fifo_output_domain,
+			 "Flush of FIFO \"{}\" failed: %s",
+			 path_utf8, strerror(errno));
 	}
 }
 

src/output/plugins/OssOutputPlugin.cxx

@@ -186,9 +186,9 @@ oss_output_test_default_device() noexcept
 		if (fd.Open(default_devices[i], O_WRONLY, 0))
 			return true;
 
-		FormatErrno(oss_output_domain,
-			    "Error opening OSS device \"%s\"",
-			    default_devices[i]);
+		FmtError(oss_output_domain,
+			 "Error opening OSS device \"{}\": {}",
+			 default_devices[i], strerror(errno));
 	}
 
 	return false;
@@ -233,8 +233,8 @@ oss_open_default(
 				   "{}: permission denied", dev);
 			break;
 		case OSS_STAT_OTHER:
-			FormatErrno(oss_output_domain, err[i],
-				    "Error accessing %s", dev);
+			FmtError(oss_output_domain, "Error accessing {}: {}",
+				 dev, strerror(err[i]));
 		}
 	}