ssh: double fclose() in sshkey_save_public()

[Tobias Heider]

Hey,

it looks like in sshkey_save_public() the same fd will be closed twice
if the first fclose() returns something other than 0.

The patch below should make sure everything only gets closed once.
I moved the close() call and refactored a bit to improve readability.

Index: authfile.c
===================================================================
RCS file: /cvs/src/usr.bin/ssh/authfile.c,v
retrieving revision 1.142
diff -u -p -r1.142 authfile.c
--- authfile.c  1 Jan 2022 01:55:30 -0000       1.142
+++ authfile.c  10 May 2022 21:38:29 -0000
@@ -496,20 +496,25 @@ sshkey_save_public(const struct sshkey *
                return SSH_ERR_SYSTEM_ERROR;
        if ((f = fdopen(fd, "w")) == NULL) {
                r = SSH_ERR_SYSTEM_ERROR;
+               close(fd);
                goto fail;
        }
        if ((r = sshkey_write(key, f)) != 0)
                goto fail;
        fprintf(f, " %s\n", comment);
-       if (ferror(f) || fclose(f) != 0) {
+       if (ferror(f)) {
                r = SSH_ERR_SYSTEM_ERROR;
+               goto fail;
+       }
+       if (fclose(f) != 0) {
+               r = SSH_ERR_SYSTEM_ERROR;
+               f = NULL;
  fail:
-               oerrno = errno;
-               if (f != NULL)
+               if (f != NULL) {
+                       oerrno = errno;
                        fclose(f);
-               else
-                       close(fd);
-               errno = oerrno;
+                       errno = oerrno;
+               }
                return r;
        }
        return 0;