swtpm: Remove stale parameter from function documentation

Signed-off-by: Stefan Berger <stefanb@linux.ibm.com>
diff --git a/src/swtpm/ctrlchannel.c b/src/swtpm/ctrlchannel.c
index 9fea6cb..d13353d 100644
--- a/src/swtpm/ctrlchannel.c
+++ b/src/swtpm/ctrlchannel.c
@@ -473,7 +473,6 @@
  *               this function in case TPM is stopped or started
  * @mlp: mainloop parameters used; may be altered by this function incase of
  *       CMD_SET_DATAFD
- * @tpmversion: the emulated TPM's version
  *
  * This function returns the passed file descriptor or -1 in case the
  * file descriptor was closed.