ptpd: Fix reserved word 'class'

When ptpd.h is included in C++ code, the use of identifier 'class'
caused a compilation error. Changed to "clockclass".

include/netutils/ptpd.h

@@ -48,7 +48,7 @@ struct ptpd_status_s
     uint8_t id[8];     /* Clock identity */
     int utcoffset;     /* Offset between clock time and UTC time (seconds) */
     int priority1;     /* Main priority field */
-    int class;         /* Clock class (IEEE-1588, lower is better) */
+    int clockclass;    /* Clock class (IEEE-1588, lower is better) */
     int accuracy;      /* Clock accuracy (IEEE-1588, lower is better) */
     int variance;      /* Clock variance (IEEE-1588, lower is better) */
     int priority2;     /* Secondary priority field */

netutils/ptpd/ptpd.c

@@ -1342,7 +1342,7 @@ static void ptp_process_statusreq(FAR struct ptp_state_s *state)
       status->clock_source_info.utcoffset =
           (int16_t)(((uint16_t)s->utcoffset[0] << 8) | s->utcoffset[1]);
       status->clock_source_info.priority1 = s->gm_priority1;
-      status->clock_source_info.class = s->gm_quality[0];
+      status->clock_source_info.clockclass = s->gm_quality[0];
       status->clock_source_info.accuracy = s->gm_quality[1];
       status->clock_source_info.priority2 = s->gm_priority2;
       status->clock_source_info.variance =

system/ptpd/ptpd_main.c

@@ -77,7 +77,7 @@ static int do_ptpd_status(int pid)
 
       printf("|- utcoffset: %d\n", status.clock_source_info.utcoffset);
       printf("|- priority1: %d\n", status.clock_source_info.priority1);
-      printf("|- class: %d\n", status.clock_source_info.class);
+      printf("|- class: %d\n", status.clock_source_info.clockclass);
       printf("|- accuracy: %d\n", status.clock_source_info.accuracy);
       printf("|- variance: %d\n", status.clock_source_info.variance);
       printf("|- priority2: %d\n", status.clock_source_info.priority2);