Don't check for -L options that gcc doesn't use.

GCC on fedora 18 ARM only uses 2 -L options. Clang prints two extra ones, but
we should not include them in the test as they are not required.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@193430 91177308-0d34-0410-b5e6-96231b3b80d8