liblp: fix host lpdump cannot work issue

If a relative path is provided on linux host, lpdump will not
work because GetPartitionAbsolutePath return an incorrect pathname.

Test: lpdump super.img

Change-Id: I7d0f10110eb72745edba810bdf288e2506bfedd6
Signed-off-by: lijiazi <lijiazi@xiaomi.com>

fs_mgr/liblp/partition_opener.cpp

@@ -38,6 +38,9 @@ using android::base::unique_fd;
 namespace {
 
 std::string GetPartitionAbsolutePath(const std::string& path) {
+#if !defined(__ANDROID__)
+    return path;
+#else
     if (android::base::StartsWith(path, "/")) {
         return path;
     }
@@ -56,6 +59,7 @@ std::string GetPartitionAbsolutePath(const std::string& path) {
         }
     }
     return by_name;
+#endif
 }
 
 bool GetBlockDeviceInfo(const std::string& block_device, BlockDeviceInfo* device_info) {