Remove unwanted newline.

The error message is included in parentheses as part of a larger error
message, so you don't want a newline at the end.

Change-Id: Iabff74941972504770c45b94b124e25d124b512c
Reviewed-on: https://code.wireshark.org/review/36441
Reviewed-by: Guy Harris <guy@alum.mit.edu>

rawshark.c

@@ -893,7 +893,7 @@ raw_pipe_read(wtap_rec *rec, Buffer *buf, int *err, gchar **err_info, gint64 *da
 #endif
     if (bytes_needed > WTAP_MAX_PACKET_SIZE_STANDARD) {
         *err = WTAP_ERR_BAD_FILE;
-        *err_info = g_strdup_printf("Bad packet length: %lu\n",
+        *err_info = g_strdup_printf("Bad packet length: %lu",
                    (unsigned long) bytes_needed);
         return FALSE;
     }