[compiler-rt][scudo][LIT] Use target_suffix instead of target-arch

Per target runtime dir may change the suffix of shared libs.
We can not assume we are always building with per_target_runtime_dir on.

Reviewed By: cryptoad

Differential Revision: https://reviews.llvm.org/D80243

compiler-rt/test/scudo/lit.cfg.py

@@ -10,7 +10,7 @@
 
 # Path to the shared library
 shared_libscudo = os.path.join(config.compiler_rt_libdir, "libclang_rt.scudo%s.so" % config.target_suffix)
-shared_minlibscudo = os.path.join(config.compiler_rt_libdir, "libclang_rt.scudo_minimal-%s.so" % config.target_arch)
+shared_minlibscudo = os.path.join(config.compiler_rt_libdir, "libclang_rt.scudo_minimal%s.so" % config.target_suffix)
 
 # Test suffixes.
 config.suffixes = ['.c', '.cpp', '.test']