libcamera: Standardize on doxygen \return

Two occasions in the source utilise the Doxygen '\returns' alias for \return.
We use \return everywhere else in the code. Update the two occurences to match.

Signed-off-by: Kieran Bingham <kieran.bingham@ideasonboard.com>
Reviewed-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>

src/libcamera/utils.cpp

@@ -55,7 +55,7 @@ const char *basename(const char *path)
  * avoid vulnerabilities that could occur if set-user-ID or set-group-ID
  * programs accidentally trust the environment.
  *
- * \returns A pointer to the value in the environment or NULL if the requested
+ * \return A pointer to the value in the environment or NULL if the requested
  * environment variable doesn't exist or if secure execution is required.
  */
 char *secure_getenv(const char *name)