package/wolfssl: cleanup version/download logic

Use the github macro rather than manually downloading from github and
include -stable in the version number to match release-monitoring.org.

And update the .hash line to match.

Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/wolfssl/wolfssl.hash

@@ -1,5 +1,5 @@
 # Locally computed:
-sha256 3562af485c26cd7abe94d9404fbfc0c5c9bceb4aab29b81ebf5e6c2467507e12 v4.2.0-stable.tar.gz
+sha256 3562af485c26cd7abe94d9404fbfc0c5c9bceb4aab29b81ebf5e6c2467507e12 wolfssl-4.2.0-stable.tar.gz
 
 # Hash for license files:
 sha256 8177f97513213526df2cf6184d8ff986c675afb514d4e68a404010521b880643  COPYING

package/wolfssl/wolfssl.mk

@@ -4,9 +4,8 @@
 #
 ################################################################################
 
-WOLFSSL_VERSION = 4.2.0
-WOLFSSL_SITE = https://github.com/wolfSSL/wolfssl/archive
-WOLFSSL_SOURCE = v$(WOLFSSL_VERSION)-stable.tar.gz
+WOLFSSL_VERSION = 4.2.0-stable
+WOLFSSL_SITE = $(call github,wolfSSL,wolfssl,v$(WOLFSSL_VERSION))
 WOLFSSL_INSTALL_STAGING = YES
 
 WOLFSSL_LICENSE = GPL-2.0