jtag: Rename 'hasidcode' to 'has_idcode'

While at it, fix some coding style issues.

Change-Id: I8196045f46ce043ed0d28cb95470132b3a7de1bb
Signed-off-by: Marc Schink <dev@zapb.de>
Reviewed-on: https://review.openocd.org/c/openocd/+/8039
Tested-by: jenkins
Reviewed-by: Antonio Borneo <borneo.antonio@gmail.com>

src/target/dsp563xx.c

@@ -912,7 +912,7 @@ static int dsp563xx_examine(struct target *target)
 {
 	uint32_t chip;
 
-	if (target->tap->hasidcode == false) {
+	if (!target->tap->has_idcode) {
 		LOG_ERROR("no IDCODE present on device");
 		return ERROR_COMMAND_SYNTAX_ERROR;
 	}