genksyms: close ref_file after use

It is the last place when the file is read, so close it.
Signed-off-by: Alexander Beregalov <a.beregalov@gmail.com>
Signed-off-by: Michal Marek <mmarek@suse.cz>

scripts/genksyms/genksyms.c

@@ -758,8 +758,10 @@ int main(int argc, char **argv)
 		/* setlinebuf(debugfile); */
 	}
 
-	if (flag_reference)
+	if (flag_reference) {
 		read_reference(ref_file);
+		fclose(ref_file);
+	}
 
 	yyparse();