Modules: Remove an extra early return, NFC

Remove an early return from an `else` block that's immediately followed
by an equivalent early return after the `else` block.

Differential Revision: https://reviews.llvm.org/D101671

clang/lib/Frontend/CompilerInstance.cpp

@@ -1890,8 +1890,6 @@ CompilerInstance::loadModule(SourceLocation ImportLoc,
       return Result;
     Module = Result;
     MM.cacheModuleLoad(*Path[0].first, Module);
-    if (!Module)
-      return Module;
   }
 
   // If we never found the module, fail.  Otherwise, verify the module and link