disk_interface: De-duplicate RemoveFile on Windows

Remove use of `DeleteFileA` and simply fall back to the original
implementation using `remove()` on all platforms.

src/disk_interface.cc

@@ -275,15 +275,7 @@ int RealDiskInterface::RemoveFile(const string& path) {
     // Skip error checking.  If this fails, accept whatever happens below.
     SetFileAttributesA(path.c_str(), attributes & ~FILE_ATTRIBUTE_READONLY);
   }
-  if (!DeleteFileA(path.c_str())) {
-    DWORD win_err = GetLastError();
-    if (win_err == ERROR_FILE_NOT_FOUND || win_err == ERROR_PATH_NOT_FOUND) {
-      return 1;
-    }
-    Error("DeleteFileA(%s): %s", path.c_str(), GetLastErrorString().c_str());
-    return -1;
-  }
-#else
+#endif
   if (remove(path.c_str()) < 0) {
     switch (errno) {
       case ENOENT:
@@ -293,7 +285,6 @@ int RealDiskInterface::RemoveFile(const string& path) {
         return -1;
     }
   }
-#endif
   return 0;
 }