ctr_drbg: Typo fix in the file description comment.
* This file is part of mbed TLS (https://tls.mbed.org)
*/
/*
- * The NIST SP 800-90 DRBGs are described in the following publucation.
+ * The NIST SP 800-90 DRBGs are described in the following publication.
*
* http://csrc.nist.gov/publications/nistpubs/800-90/SP800-90revised_March2007.pdf
*/
