[build] several bugs fixed

[alex-ht]

Problem 1:

$ cmake -DKALDI_USE_PATCH_NUMBER=ON ../
$ make
Scanning dependencies of target fst
[  0%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/compat.cc.o
[  0%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/flags.cc.o
[  1%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/fst-types.cc.o
[  1%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/fst.cc.o
[  1%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/mapped-file.cc.o
[  2%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/properties.cc.o
[  2%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/symbol-table-ops.cc.o
[  2%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/symbol-table.cc.o
[  3%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/util.cc.o
[  3%] Building CXX object CMakeFiles/fst.dir/openfst/src/lib/weight.cc.o
[  3%] Linking CXX static library libfst.a
[  3%] Built target fst
src/base/CMakeFiles/kaldi-base.dir/flags.make:8: *** missing separator.  Stop.
make[1]: *** [CMakeFiles/Makefile2:961: src/base/CMakeFiles/kaldi-base.dir/all] Error 2
make: *** [Makefile:150: all] Error 2

and there is an extra new line

$cat src/base/CMakeFiles/kaldi-base.dir/flags.make
# CMAKE generated file: DO NOT EDIT!
# Generated by "Unix Makefiles" Generator, CMake Version 3.17

# compile CXX with /usr/lib/ccache/c++
CXX_FLAGS =   -std=c++14

CXX_DEFINES = -DHAVE_CLAPACK=1 -DKALDI_NO_PORTAUDIO=1 -DKALDI_VERSION=\"5.5.678
\"

.....

Problem 2: configurations in cmake/third_party/openfst.cmake and CMakeLists.txt are inconsistent.