create_ifu_tag: updates from testing on rocm fork

- Need to use upstream/main for rocm/pytorch's develop branch. For
  release branches, `github.event.pull_request.base.ref` should work as
  is.

- Need to remove any trailing space in PR TITTLE so branch name can be
  formed correctly

Fixes #ISSUE_NUMBER

Author: pragupta

.github/workflows/create_ifu_tag.yml

@@ -40,6 +40,17 @@ jobs:
           HEAD_SHA="${{ github.event.pull_request.head.sha }}"
           MERGE_SHA="${{ github.event.pull_request.merge_commit_sha }}"
 
+          # For release branches, local branch is same as remote branch. But, for rocm/pytorch's
+          # develop branch, we want to use main branch upstream
+          if [ "$BASE_REF" == "develop" ]; then
+            BASE_REF="main"
+          fi
+          
+          echo "PR_NUM=$PR_NUM"                           
+          echo "BASE_REF=$BASE_REF"                       
+          echo "HEAD_SHA=$HEAD_SHA"                       
+          echo "MERGE_SHA=$MERGE_SHA"                     
+    
           # The ROCm base commit is the first parent of the merge commit that landed the PR
           # (i.e., the base branch tip BEFORE this PR merged).
           ROCM_BASE_SHA=$(git rev-parse "${MERGE_SHA}^1")
@@ -52,10 +63,6 @@ jobs:
           # between the PR head commit and upstream/main as fetched now.
           # This gives you the exact upstream commit (or the best common ancestor) that HEAD included.
           UPSTREAM_MAIN_SHA=$(git merge-base "${HEAD_SHA}" "upstream/$BASE_REF")
-          echo "PR_NUM=$PR_NUM"                           
-          echo "BASE_REF=$BASE_REF"                       
-          echo "HEAD_SHA=$HEAD_SHA"                       
-          echo "MERGE_SHA=$MERGE_SHA"                     
           echo "ROCM_BASE_SHA=$ROCM_BASE_SHA"            
           echo "UPSTREAM_MAIN_SHA=$UPSTREAM_MAIN_SHA"     
 
@@ -72,7 +79,8 @@ jobs:
         run: |
           TITLE="${{ github.event.pull_request.title }}"
           # Remove everything up to and including "[AUTOGENERATED]"
-          BASE_TAG=$(echo "$TITLE" | sed -E 's/^\[AUTOGENERATED\][[:space:]]*//')
+          # Remove trailing whitespace
+          BASE_TAG=$(echo "$TITLE" | sed -E 's/^\[AUTOGENERATED\][[:space:]]*//' | sed -E 's/[[:space:]]+$//')
 
           echo "BASE_TAG=$BASE_TAG" 
           echo "PRE_TAG=${BASE_TAG}_pre"