[ASan] Fix asan-(32|64)-bits lit tests feature.

It broke down at some point, and all tests with
  REQUIRES: asan-(32|64)-bits
line stopped being executed. Restore the intended behavior.

llvm-svn: 231325

compiler-rt/test/asan/CMakeLists.txt

@@ -5,9 +5,9 @@ set(ASAN_DYNAMIC_TESTSUITES)
 
 macro(get_bits_for_arch arch bits)
   if (${arch} MATCHES "i386|i686|arm|mips|mipsel")
-    set(bits 32)
+    set(${bits} 32)
   elseif (${arch} MATCHES "x86_64|powerpc64|powerpc64le|aarch64|mips64|mips64el")
-    set(bits 64)
+    set(${bits} 64)
   else()
     message(FATAL_ERROR "Unknown target architecture: ${arch}")
   endif()