CLEANUP: stats: improve field selection for frontend http fields

while working on backend/servers I realised I could have written that in
a better way and avoid one extra break. This is slightly improving
readiness.
also while being here, fix function declaration which was not 100%
accurate.

this patch does not change the behaviour of the code.

Signed-off-by: William Dauchy <wdauchy@gmail.com>
diff --git a/src/stats.c b/src/stats.c
index 1b8fad3..dcb99f6 100644
--- a/src/stats.c
+++ b/src/stats.c
@@ -1713,49 +1713,40 @@
 				metric = mkf_u64(FN_COUNTER, px->fe_counters.internal_errors);
 				break;
 			case ST_F_HRSP_1XX:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[1]);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[1]);
 				break;
 			case ST_F_HRSP_2XX:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[2]);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[2]);
 				break;
 			case ST_F_HRSP_3XX:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[3]);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[3]);
 				break;
 			case ST_F_HRSP_4XX:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[4]);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[4]);
 				break;
 			case ST_F_HRSP_5XX:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[5]);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[5]);
 				break;
 			case ST_F_HRSP_OTHER:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[0]);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.rsp[0]);
 				break;
 			case ST_F_INTERCEPTED:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.intercepted_req);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.intercepted_req);
 				break;
 			case ST_F_CACHE_LOOKUPS:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.cache_lookups);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.cache_lookups);
 				break;
 			case ST_F_CACHE_HITS:
-				if (px->mode != PR_MODE_HTTP)
-					break;
-				metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.cache_hits);
+				if (px->mode == PR_MODE_HTTP)
+					metric = mkf_u64(FN_COUNTER, px->fe_counters.p.http.cache_hits);
 				break;
 			case ST_F_REQ_RATE:
 				metric = mkf_u32(FN_RATE, read_freq_ctr(&px->fe_req_per_sec));