config: drop cf validity check in get_next_char()

The global variable cf is set with an initialized value in all codepaths before
calling this function.

The complete call graph looks like this:

  git_config_from_file
    -> do_config_from
      -> git_parse_file
        -> get_next_char
        -> get_value
            -> get_next_char
            -> parse_value
                -> get_next_char
        -> get_base_var
            -> get_next_char
            -> get_extended_base_var
                -> get_next_char

The variable is initialized in do_config_from.

Signed-off-by: Heiko Voigt <hvoigt@hvoigt.net>
Acked-by: Jeff King <peff@peff.net>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

config.c

@@ -169,10 +169,8 @@ int git_config_from_parameters(config_fn_t fn, void *data)
 static int get_next_char(void)
 {
 	int c;
-	FILE *f;
+	FILE *f = cf->f;
 
-	c = '\n';
-	if (cf && ((f = cf->f) != NULL)) {
 	c = fgetc(f);
 	if (c == '\r') {
 		/* DOS like systems */
@@ -188,7 +186,6 @@ static int get_next_char(void)
 		cf->eof = 1;
 		c = '\n';
 	}
-	}
 	return c;
 }