hla: improve readability of struct hl_interface_s initialization

The initialization is barely readable, while actually only few
fields are set with value nor zero nor NULL.

Rewrite the initialization using C99 struct designations.

Change-Id: I4d288e6536ebe7110a184db6540223fc67361ec3
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: https://review.openocd.org/c/openocd/+/6636
Tested-by: jenkins
Reviewed-by: Tomas Vanek <vanekt@fbl.cz>

src/jtag/hla/hla_interface.c

@@ -35,7 +35,21 @@
 
 #include <target/target.h>
 
-static struct hl_interface_s hl_if = { {0, 0, { 0 }, { 0 }, HL_TRANSPORT_UNKNOWN, false, -1, false, 7184}, 0, 0 };
+static struct hl_interface_s hl_if = {
+	.param = {
+		.device_desc = NULL,
+		.serial = NULL,
+		.vid = { 0 },
+		.pid = { 0 },
+		.transport = HL_TRANSPORT_UNKNOWN,
+		.connect_under_reset = false,
+		.initial_interface_speed = -1,
+		.use_stlink_tcp = false,
+		.stlink_tcp_port = 7184,
+	},
+	.layout = NULL,
+	.handle = NULL,
+};
 
 int hl_interface_open(enum hl_transports tr)
 {