selftests/xsk: use ksft_print_msg uniformly

Use ksft_print_msg() instead of printf() and fprintf() in all places
as the ksefltests framework is being used. There is only one exception
and that is for the list-of-tests print out option, since no tests are
run in that case.
Signed-off-by: Magnus Karlsson <magnus.karlsson@intel.com>
Link: https://lore.kernel.org/r/20230914084900.492-9-magnus.karlsson@gmail.comSigned-off-by: Alexei Starovoitov <ast@kernel.org>

tools/testing/selftests/bpf/xskxceiver.c

@@ -808,7 +808,7 @@ static void pkt_print_data(u32 *data, u32 cnt)
 
 		seqnum = ntohl(*data) & 0xffff;
 		pkt_nb = ntohl(*data) >> 16;
-		fprintf(stdout, "%u:%u ", pkt_nb, seqnum);
+		ksft_print_msg("%u:%u ", pkt_nb, seqnum);
 		data++;
 	}
 }
@@ -820,13 +820,13 @@ static void pkt_dump(void *pkt, u32 len, bool eth_header)
 
 	if (eth_header) {
 		/*extract L2 frame */
-		fprintf(stdout, "DEBUG>> L2: dst mac: ");
+		ksft_print_msg("DEBUG>> L2: dst mac: ");
 		for (i = 0; i < ETH_ALEN; i++)
-			fprintf(stdout, "%02X", ethhdr->h_dest[i]);
+			ksft_print_msg("%02X", ethhdr->h_dest[i]);
 
-		fprintf(stdout, "\nDEBUG>> L2: src mac: ");
+		ksft_print_msg("\nDEBUG>> L2: src mac: ");
 		for (i = 0; i < ETH_ALEN; i++)
-			fprintf(stdout, "%02X", ethhdr->h_source[i]);
+			ksft_print_msg("%02X", ethhdr->h_source[i]);
 
 		data = pkt + PKT_HDR_SIZE;
 	} else {
@@ -834,15 +834,15 @@ static void pkt_dump(void *pkt, u32 len, bool eth_header)
 	}
 
 	/*extract L5 frame */
-	fprintf(stdout, "\nDEBUG>> L5: seqnum: ");
+	ksft_print_msg("\nDEBUG>> L5: seqnum: ");
 	pkt_print_data(data, PKT_DUMP_NB_TO_PRINT);
-	fprintf(stdout, "....");
+	ksft_print_msg("....");
 	if (len > PKT_DUMP_NB_TO_PRINT * sizeof(u32)) {
-		fprintf(stdout, "\n.... ");
+		ksft_print_msg("\n.... ");
 		pkt_print_data(data + len / sizeof(u32) - PKT_DUMP_NB_TO_PRINT,
 			       PKT_DUMP_NB_TO_PRINT);
 	}
-	fprintf(stdout, "\n---------------------------------------\n");
+	ksft_print_msg("\n---------------------------------------\n");
 }
 
 static bool is_offset_correct(struct xsk_umem_info *umem, struct pkt *pkt, u64 addr)
@@ -1553,7 +1553,8 @@ static void *worker_testapp_validate_rx(void *arg)
 		xsk_clear_xskmap(ifobject->xskmap);
 		err = xsk_update_xskmap(ifobject->xskmap, ifobject->xsk->xsk);
 		if (err) {
-			printf("Error: Failed to update xskmap, error %s\n", strerror(-err));
+			ksft_print_msg("Error: Failed to update xskmap, error %s\n",
+				       strerror(-err));
 			exit_with_error(-err);
 		}
 	}
@@ -1617,7 +1618,7 @@ static void xsk_reattach_xdp(struct ifobject *ifobj, struct bpf_program *xdp_pro
 	xsk_detach_xdp_program(ifobj->ifindex, mode_to_xdp_flags(ifobj->mode));
 	err = xsk_attach_xdp_program(xdp_prog, ifobj->ifindex, mode_to_xdp_flags(mode));
 	if (err) {
-		printf("Error attaching XDP program\n");
+		ksft_print_msg("Error attaching XDP program\n");
 		exit_with_error(-err);
 	}
 
@@ -2104,7 +2105,7 @@ static void init_iface(struct ifobject *ifobj, const char *dst_mac, const char *
 
 	err = xsk_load_xdp_programs(ifobj);
 	if (err) {
-		printf("Error loading XDP program\n");
+		ksft_print_msg("Error loading XDP program\n");
 		exit_with_error(err);
 	}