globals.hh: don't use '==' to compare string literals

Saw this in logs, also reported here: 8e6108ff71 (r28707288)
2018-04-23 20:57:05 -05:00 · 2018-04-23 20:57:05 -05:00 · 8e7d77d494
parent 8e6108ff71
commit 8e7d77d494
1 changed files with 1 additions and 1 deletions
--- a/src/libstore/globals.hh
+++ b/src/libstore/globals.hh
@ -296,7 +296,7 @@ public:
        "listed in 'trusted-public-keys'."};

    Setting<StringSet> extraPlatforms{this,
-        SYSTEM == "x86_64-linux" ? StringSet{"i686-linux"} : StringSet{},
+        std::string{SYSTEM} == "x86_64-linux" ? StringSet{"i686-linux"} : StringSet{},
        "extra-platforms",
        "Additional platforms that can be built on the local system. "
        "These may be supported natively (e.g. armv7 on some aarch64 CPUs "