patch 8.2.0966: 'shortmess' flag "n" not used in two places

Problem:    'shortmess' flag "n" not used in two places.
Solution:   Make use of the "n" flag consistent. (Nick Jensen, closes #6245,
            closes #6244)
diff --git a/src/buffer.c b/src/buffer.c
index 66b0050..f928412 100644
--- a/src/buffer.c
+++ b/src/buffer.c
@@ -3651,7 +3651,7 @@
 #ifdef FEAT_QUICKFIX
 		    && !bt_dontwrite(curbuf)
 #endif
-					? _("[New file]") : "",
+					   ? new_file_message() : "",
 	    (curbuf->b_flags & BF_READERR) ? _("[Read errors]") : "",
 	    curbuf->b_p_ro ? (shortmess(SHM_RO) ? _("[RO]")
 						      : _("[readonly]")) : "",