A few minor tweaks about HPHP_HOME

I think everything should work without it now.

hphp/compiler/option.cpp

@@ -161,7 +161,8 @@ std::string Option::GetSystemRoot() {
   if (SystemRoot.empty()) {
     const char *home = getenv("HPHP_HOME");
     if (!home || !*home) {
-      throw Exception("Environment variable HPHP_HOME is not set.");
+      throw Exception("Environment variable HPHP_HOME is not set, "
+                      "and neither is the SystemRoot option.");
     }
     SystemRoot = home;
     SystemRoot += "/hphp";

hphp/test/run

@@ -73,8 +73,8 @@ function idx_file($array, $key, $default = null) {
 }
 
 function bin_root() {
-  return idx($_ENV, 'FBMAKE_BIN_ROOT', 
-    is_dir(hphp_home().'/_bin') ? 
+  return idx($_ENV, 'FBMAKE_BIN_ROOT',
+    is_dir(hphp_home().'/_bin') ?
       hphp_home().'/_bin' : # fbmake
       hphp_home() # github
   );