Cleanup. NFC

llvm-svn: 334357
diff --git a/llvm/lib/Support/Unix/Process.inc b/llvm/lib/Support/Unix/Process.inc
index 68baab8..43ba6d6 100644
--- a/llvm/lib/Support/Unix/Process.inc
+++ b/llvm/lib/Support/Unix/Process.inc
@@ -79,7 +79,7 @@
 #elif defined(HAVE_SYSCONF)
   static long page_size = ::sysconf(_SC_PAGE_SIZE);
 #else
-#warning Cannot get the page size on this machine
+#error Cannot get the page size on this machine
 #endif
   return static_cast<unsigned>(page_size);
 }