Fix jtag_usb_location_equal for path members > 9

In case an USB location path contains path members
larger than 9. The string_length variable is regardless
decremented by 2 with assumption that the member is
one digit length. For exmaple 1-12.2 will fail.
This patch uses strlen to calculate
digits in a path member.

Change-Id: I9c26a04d0c6af13fec65157f222599497294e2b2
Signed-off-by: Krzysztof Hockuba <[email protected]>
Reviewed-on: http://openocd.zylin.com/6048
Tested-by: jenkins
Reviewed-by: Antonio Borneo <[email protected]>

Author: Krzysztof Hockuba

src/jtag/drivers/jtag_usb_common.c

@@ -50,7 +50,7 @@ bool jtag_usb_location_equal(uint8_t dev_bus, uint8_t *port_path,
 		goto done;
 	}
 
-	string_length -= 1;
+	string_length -= strnlen(ptr, string_length);
 	/* check bus mismatch */
 	if (atoi(ptr) != dev_bus)
 		goto done;
@@ -68,7 +68,7 @@ bool jtag_usb_location_equal(uint8_t dev_bus, uint8_t *port_path,
 			break;
 
 		path_step++;
-		string_length -= 2;
+		string_length -= strnlen(ptr, string_length) + 1;
 	};
 
 	/* walked the full path, all elements match */