Fix yet another occasions of 'setup' vs. 'set up' typo in x509_crt.h
diff --git a/include/mbedtls/x509_crt.h b/include/mbedtls/x509_crt.h
index 77609ef..2fb26fd 100644
--- a/include/mbedtls/x509_crt.h
+++ b/include/mbedtls/x509_crt.h
@@ -664,7 +664,7 @@
mbedtls_x509_crt_frame *dst );
/**
- * \brief Setup a PK context with the public key in a certificate.
+ * \brief Set up a PK context with the public key in a certificate.
*
* \param crt The certificate to use. This must be initialized and set up.
* \param pk The address of the destination PK context to fill.