Close file descriptors in case fdopen() fails

This makes sure that file descriptors will be closed, even if the
fdopen() call failes, which was overlooked in some cases beforehand.
Should be not an issue in the real world, but let's be as clean as
possible.

pam_yubico.c

@@ -833,7 +833,9 @@ parse_cfg (int flags, int argc, const char **argv, struct cfg *cfg)
                           if (file)
                             {
                               cfg->debug_file = file;
-                            }
+                            } else {
+			      close(fd);
+			    }
                         }
                     }
                 }

util.c

@@ -203,6 +203,7 @@ int generate_random(void *buf, int len)
 
 	u = fdopen(fd, "r");
 	if (!u) {
+		close(fd);
 		return -1;
 	}
 

ykpamcfg.c

@@ -258,6 +258,7 @@ do_add_hmac_chalresp(YK_KEY *yk, uint8_t slot, bool verbose, char *output_dir, u
   f = fdopen (fd, "w");
   if (! f) {
     fprintf (stderr, "fdopen: %s\n", strerror (errno));
+    close(fd);
     goto out;
   }