No need to complicate make-docfile.c for Clang

* lib-src/make-docfile.c (put_filename): Undo recent change.
The Clang false alarm occurs only with CFLAGS=-save-temps and
we needn’t worry about pacifying unusual compiler configurations.

lib-src/make-docfile.c

@@ -224,11 +224,7 @@ put_filename (char *filename)
 
   for (tmp = filename; *tmp; tmp++)
     {
-      /* Use separate variable to silence a Clang warning on macOS.
-         Clang takes offence of the additional set of parantheses
-         generated by the macro.  */
-      bool is_sep = IS_DIRECTORY_SEP (*tmp);
-      if (is_sep)
+      if (IS_DIRECTORY_SEP (*tmp))
 	filename = tmp + 1;
     }