AP_HAL_Linux: move dirname to I2CDevice core

All entries would need the "devices/" prefix and it's more natural not
using it.

libraries/AP_HAL_Linux/HAL_Linux_Class.cpp

@@ -55,9 +55,9 @@ static I2CDriver i2cDriver0(2);
 #elif CONFIG_HAL_BOARD_SUBTYPE == HAL_BOARD_SUBTYPE_LINUX_MINLURE
 static const std::vector<const char *> i2c_devpaths({
     /* UEFI with lpss set to ACPI */
-    "/devices/platform/80860F41:05",
+    "platform/80860F41:05",
     /* UEFI with lpss set to PCI */
-    "/devices/pci0000:00/0000:00:18.6",
+    "pci0000:00/0000:00:18.6",
 });
 static I2CDriver  i2cDriver0(i2c_devpaths);
 /* One additional emulated bus */

libraries/AP_HAL_Linux/I2CDevice.cpp

@@ -223,7 +223,7 @@ I2CDeviceManager::I2CDeviceManager()
 AP_HAL::OwnPtr<AP_HAL::I2CDevice>
 I2CDeviceManager::get_device(std::vector<const char *> devpaths, uint8_t address)
 {
-    const char *dirname = "/sys/class/i2c-dev";
+    const char *dirname = "/sys/class/i2c-dev/";
     struct dirent *de = nullptr;
     DIR *d;
 
@@ -245,7 +245,7 @@ I2CDeviceManager::get_device(std::vector<const char *> devpaths, uint8_t address
         }
 
         abs_str_device = realpath(str_device, nullptr);
-        if (!abs_str_device || !(p = startswith(abs_str_device, "/sys"))) {
+        if (!abs_str_device || !(p = startswith(abs_str_device, "/sys/devices/"))) {
             free(abs_str_device);
             free(str_device);
             continue;