[PATCH] xentrace: free CPU mask string before overwriting pointer

[Jan Beulich <jbeulich@suse.com>]

While multiple -c options may be unexpected, we'd still better deal with
them properly.

Also restore the blank line that was bogusly zapped by the same commit.

Coverity-ID: 1638723
Fixes: e4ad2836842a ("xentrace: Implement cpu mask range parsing of human values (-c)")
Signed-off-by: Jan Beulich <jbeulich@suse.com>

--- a/tools/xentrace/xentrace.c
+++ b/tools/xentrace/xentrace.c
@@ -1105,8 +1105,10 @@ static void parse_args(int argc, char **
             break;
 
         case 'c': /* set new cpu mask for filtering (when xch is set). */
+            free(opts.cpu_mask_str);
             opts.cpu_mask_str = strdup(optarg);
             break;
+
         case 'e': /* set new event mask for filtering*/
             parse_evtmask(optarg);
             break;