doc: fix typo for osmo_hexparse

Change-Id: Ifc2b499792fda378c807c678b8e06630cb64d273
diff --git a/src/utils.c b/src/utils.c
index 1bb2be8..02c2443 100644
--- a/src/utils.c
+++ b/src/utils.c
@@ -118,7 +118,7 @@
 	return c - 0x30;
 }
 
-/*! \brief Parse a string ocntaining hexadecimal digits
+/*! \brief Parse a string containing hexadecimal digits
  *  \param[in] str string containing ASCII encoded hexadecimal digits
  *  \param[out] b output buffer
  *  \param[in] max_len maximum space in output buffer