package/openpgm: drop release- prefix to match release-monitoring.org

Autobuild has a "version bump" checker that sends message to a package
maintainer if its declared version does not match the latest one on
release-monitoring.org.  In case of openpgm the version _is_ the latest one,
but a mismatch is caused by including a "release-" prefix into tags on
upstream and excluding them on other websites when referring to the
package's version.

This also fixes sha256 value for the downloaded archive.

Signed-off-by: Alexander Lukichev <alexander.lukichev@gmail.com>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/openpgm/openpgm.hash

@@ -1,2 +1,2 @@
 # Locally calculated
-sha256 ecd48fd0bcfd8351ce6dcf31b063dd8fe83d3dab41bca62a6ebd6880a88c4a69  openpgm-release-5-2-122.tar.gz
+sha256 acc1545fd8060aa66b17327110e2859e451cfc685ebd3b2211619728e3471b66  openpgm-5-2-122.tar.gz

package/openpgm/openpgm.mk

@@ -4,8 +4,8 @@
 #
 ################################################################################
 
-OPENPGM_VERSION = release-5-2-122
-OPENPGM_SITE = $(call github,steve-o,openpgm,$(OPENPGM_VERSION))
+OPENPGM_VERSION = 5-2-122
+OPENPGM_SITE = $(call github,steve-o,openpgm,release-$(OPENPGM_VERSION))
 OPENPGM_LICENSE = LGPL-2.1+
 OPENPGM_LICENSE_FILES = openpgm/pgm/LICENSE
 OPENPGM_INSTALL_STAGING = YES