diff: use designated initializers for emitted_diff_symbol

This makes it clearer which fields are being explicitly initialized
and will simplify the next commit where we add a new field to the
struct.

Signed-off-by: Phillip Wood <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: phillipwood

diff.c

@@ -1497,7 +1497,9 @@ static void emit_diff_symbol_from_struct(struct diff_options *o,
 static void emit_diff_symbol(struct diff_options *o, enum diff_symbol s,
 			     const char *line, int len, unsigned flags)
 {
-	struct emitted_diff_symbol e = {line, len, flags, 0, 0, s};
+	struct emitted_diff_symbol e = {
+		.line = line, .len = len, .flags = flags, .s = s
+	};
 
 	if (o->emitted_symbols)
 		append_emitted_diff_symbol(o, &e);