[libFuzzer] Remove FuzzerCommand.cpp from build sources.
[libFuzzer] Remove FuzzerCommand.cpp from build sources.

FuzzerCommand.cpp was not introduced in r319680.  Instead, it was
implemented in the header file.

git-svn-id: c199f293c43da69278bea8e88f92242bf3aa95f7@319682 91177308-0d34-0410-b5e6-96231b3b80d8

llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt,llvm-mirror/compiler-rt