various spelling fixes

Reviewed-by: Richard Levitte <levitte@openssl.org>
Reviewed-by: Rich Salz <rsalz@openssl.org>
(Merged from https://github.com/openssl/openssl/pull/952)
diff --git a/apps/apps.c b/apps/apps.c
index a80a07e..60a2728 100644
--- a/apps/apps.c
+++ b/apps/apps.c
@@ -1966,9 +1966,9 @@
  * in a format suitable for passing to SSL_CTX_set_next_protos_advertised.
  *   outlen: (output) set to the length of the resulting buffer on success.
  *   err: (maybe NULL) on failure, an error message line is written to this BIO.
- *   in: a NUL termianted string like "abc,def,ghi"
+ *   in: a NUL terminated string like "abc,def,ghi"
  *
- *   returns: a malloced buffer or NULL on failure.
+ *   returns: a malloc'd buffer or NULL on failure.
  */
 unsigned char *next_protos_parse(size_t *outlen, const char *in)
 {