openocd: manually remove NULL comparisons

For the remaining NULL comparisons, remove then manually.

While there, make more readable a loop, by moving the assigment
out of the loop condition.

Change-Id: I44193aaa95813156a3a79c16b80e1ad333dc1eaf
Signed-off-by: Antonio Borneo <borneo.antonio@gmail.com>
Reviewed-on: http://openocd.zylin.com/6353
Tested-by: jenkins

src/target/target.c

@@ -484,7 +484,7 @@ struct target *get_target(const char *id)
 
 	/* try as tcltarget name */
 	for (target = all_targets; target; target = target->next) {
-		if (target_name(target) == NULL)
+		if (!target_name(target))
 			continue;
 		if (strcmp(id, target_name(target)) == 0)
 			return target;