jobs: include hotfix name in Slack notifications

Otherwise, the Slack notifications look just like the regular ones for
the official streams the hotfix build is based on. We noticed this when
testing the hotfix workflow recently.

Author: jlebon

jobs/build-arch.Jenkinsfile

@@ -393,7 +393,11 @@ lock(resource: "build-${params.STREAM}-${basearch}") {
     throw e
 } finally {
     def color
-    def message = "[${params.STREAM}][${basearch}] <${env.BUILD_URL}|${env.BUILD_NUMBER}>"
+    def stream = params.STREAM
+    if (pipecfg.hotfix) {
+        stream += "-${pipecfg.hotfix.name}"
+    }
+    def message = "[${stream}][${basearch}] <${env.BUILD_URL}|${env.BUILD_NUMBER}>"
 
     if (currentBuild.result == 'SUCCESS') {
         if (!newBuildID) {

jobs/build.Jenkinsfile

@@ -484,7 +484,11 @@ lock(resource: "build-${params.STREAM}") {
     throw e
 } finally {
     def color
-    def message = "[${params.STREAM}][${basearch}] <${env.BUILD_URL}|${env.BUILD_NUMBER}>"
+    def stream = params.STREAM
+    if (pipecfg.hotfix) {
+        stream += "-${pipecfg.hotfix.name}"
+    }
+    def message = "[${stream}][${basearch}] <${env.BUILD_URL}|${env.BUILD_NUMBER}>"
 
     if (currentBuild.result == 'SUCCESS') {
         if (!newBuildID) {

jobs/release.Jenkinsfile

@@ -378,5 +378,9 @@ lock(resource: "release-${params.STREAM}", extra: locks) {
     currentBuild.result = 'FAILURE'
     throw e
 } finally {
-    pipeutils.trySlackSend(message: ":bullettrain_front: release <${env.BUILD_URL}|#${env.BUILD_NUMBER}> [${params.STREAM}][${basearches.join(' ')}] (${params.VERSION})")
+    def stream = params.STREAM
+    if (pipecfg.hotfix) {
+        stream += "-${pipecfg.hotfix.name}"
+    }
+    pipeutils.trySlackSend(message: ":bullettrain_front: release <${env.BUILD_URL}|#${env.BUILD_NUMBER}> [${stream}][${basearches.join(' ')}] (${params.VERSION})")
 }}} // try-catch-finally, cosaPod and lock finish here