perf jevents: Handle header line in mapfile

To work with existing mapfiles, assume that the first line in
'mapfile.csv' is a header line and skip over it.

Signed-off-by: Sukadev Bhattiprolu <sukadev@linux.vnet.ibm.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Jiri Olsa <jolsa@redhat.com>
Cc: Madhavan Srinivasan <maddy@linux.vnet.ibm.com>
Cc: Peter Zijlstra <peterz@infradead.org>
Link: http://lkml.kernel.org/r/1473978296-20712-15-git-send-email-sukadev@linux.vnet.ibm.com
Cc: linuxppc-dev@lists.ozlabs.org
Signed-off-by: Andi Kleen <ak@linux.intel.com>
Signed-off-by: Arnaldo Carvalho de Melo <acme@redhat.com>

tools/perf/pmu-events/jevents.c

@@ -477,7 +477,12 @@ static int process_mapfile(FILE *outfp, char *fpath)
 
 	print_mapping_table_prefix(outfp);
 
-	line_num = 0;
+	/* Skip first line (header) */
+	p = fgets(line, n, mapfp);
+	if (!p)
+		goto out;
+
+	line_num = 1;
 	while (1) {
 		char *cpuid, *version, *type, *fname;
 
@@ -521,8 +526,8 @@ static int process_mapfile(FILE *outfp, char *fpath)
 		fprintf(outfp, "},\n");
 	}
 
+out:
 	print_mapping_table_suffix(outfp);
-
 	return 0;
 }