xz: Fix displaying of file sizes in progress indicator in passthru mode.

It worked for one input file since the counters are zero when
xz starts but they weren't reset when starting a new file in
passthru mode. For example, if files A, B, and C are one byte each,
then "xz -dcvf A B C" would show file sizes as 1, 2, and 3 bytes
instead of 1, 1, and 1 byte.

src/xz/coder.c

@@ -560,8 +560,12 @@ coder_init(file_pair *pair)
 			// is needed, because we don't want to do use
 			// passthru mode with --test.
 			if (opt_mode == MODE_DECOMPRESS
-					&& opt_stdout && opt_force)
+					&& opt_stdout && opt_force) {
+				// These are needed for progress info.
+				strm.total_in = 0;
+				strm.total_out = 0;
 				return CODER_INIT_PASSTHRU;
+			}
 
 			ret = LZMA_FORMAT_ERROR;
 			break;