beckham: gpt-utils: Address the warnings

[ 11% 2/18] target  C++: libgptutils <= device/google/crosshatch/gpt-utils/gpt-utils.cpp
In file included from device/google/crosshatch/gpt-utils/gpt-utils.cpp:54:
system/core/libcutils/include_vndk/cutils/log.h:38:2: warning: "Deprecated: don't include cutils/log.h, use either android/log.h or log/log.h" [-W#warnings]
 ^
device/google/crosshatch/gpt-utils/gpt-utils.cpp:750:17: warning: unused variable 'ufs_dir_stat' [-Wunused-variable]
    struct stat ufs_dir_stat;
                ^
device/google/crosshatch/gpt-utils/gpt-utils.cpp:973:13: warning: unused variable 'r' [-Wunused-variable]
        int r, fd;
            ^
device/google/crosshatch/gpt-utils/gpt-utils.cpp:973:16: warning: unused variable 'fd' [-Wunused-variable]
        int r, fd;
               ^
4 warnings generated.

Test: lunch blueline-userdebug && m -j libgptutils
Change-Id: Idd9174276d8a5b7b77c2ec48c745a78184f65fcf