Remove extra semi colon from mcrouter/lib/fbi/hash.c

Summary:
`-Wextra-semi` or `-Wextra-semi-stmt`

If the code compiles, this is safe to land.

Reviewed By: palmje

Differential Revision: D54362223

fbshipit-source-id: 6d030eec5afd75c1685d4818f8088772965769df

multipy/runtime/loader.cpp

@@ -293,7 +293,7 @@ __attribute__((noinline)) void __deploy_register_code() {
   for (i = 0; i < 10; i++) {
     __asm__ volatile("" : "+g"(i) : :);
   }
-};
+}
 
 struct DeployModuleInfo {
   const char* name;