Speculative buildbot fix.

Author: pcc

compiler-rt/test/lit.common.configured.in

@@ -10,7 +10,7 @@ set_default("target_triple", "@COMPILER_RT_DEFAULT_TARGET_TRIPLE@")
 set_default("target_cflags", "@COMPILER_RT_TEST_COMPILER_CFLAGS@")
 set_default("host_arch", "@HOST_ARCH@")
 set_default("target_arch", "@COMPILER_RT_DEFAULT_TARGET_ARCH@")
-set_default("host_os", "@HOST_OS@")
+set_default("target_os", "@HOST_OS@")
 set_default("llvm_build_mode", "@LLVM_BUILD_MODE@")
 set_default("llvm_src_root", "@LLVM_MAIN_SRC_DIR@")
 set_default("llvm_obj_root", "@LLVM_BINARY_DIR@")