vim-patch:9.0.0733: use of strftime() is not safe (#21228)

Problem:    Use of strftime() is not safe.
Solution:   Check the return value of strftime().  Use a larger buffer and
            correctly pass the available space. (Dominique Pellé, closes
            vim/vim#11348)

84d14ccdb5

Co-authored-by: Dominique Pelle <dominique.pelle@gmail.com>

src/nvim/memline.c

@@ -1461,7 +1461,7 @@ static time_t swapfile_info(char_u *fname)
     msg_puts(_("             dated: "));
 #endif
     x = file_info.stat.st_mtim.tv_sec;
-    char ctime_buf[50];
+    char ctime_buf[100];  // hopefully enough for every language
     msg_puts(os_ctime_r(&x, ctime_buf, sizeof(ctime_buf)));
   }