sync: don't check and warn about non-empty merges anymore

Initial versions of sync script couldn't handle non-empty merges. But since
then, script became smarter, more interactive and thus more powerful and can
handle some complicated situations easily on its own, while falling back to
human intervention for even more complicated situations. This non-empty merge
check has outlived its purpose and is just an annoying bump in sync process.
Drop it.

Signed-off-by: Andrii Nakryiko <andriin@fb.com>

scripts/sync-kernel.sh

@@ -85,36 +85,6 @@ commit_signature()
 	git show --pretty='("%s")|%aI|%b' --shortstat $1 -- ${2-.} | tr '\n' '|'
 }
 
-# Validate there are no non-empty merges (we can't handle them)
-# $1 - baseline tag
-# $2 - tip tag
-validate_merges()
-{
-	local baseline_tag=$1
-	local tip_tag=$2
-	local new_merges
-	local merge_change_cnt
-	local ignore_merge_resolutions
-	local desc
-
-	new_merges=$(git rev-list --merges --topo-order --reverse ${baseline_tag}..${tip_tag} ${LIBBPF_PATHS[@]})
-	for new_merge in ${new_merges}; do
-		desc=$(commit_desc ${new_merge})
-		echo "MERGE: ${desc}"
-		merge_change_cnt=$(git show --format='' ${new_merge} | wc -l)
-		if ((${merge_change_cnt} > 0)); then
-			read -p "Merge '${desc}' is non-empty, which will cause conflicts! Do you want to proceed? [y/N]: " ignore_merge_resolutions
-			case "${ignore_merge_resolutions}" in
-				"y" | "Y")
-					echo "Skipping '${desc}'..."
-					continue
-					;;
-			esac
-			exit 3
-		fi
-	done
-}
-
 # Cherry-pick commits touching libbpf-related files
 # $1 - baseline_tag
 # $2 - tip_tag
@@ -243,10 +213,6 @@ git branch ${BPF_TIP_TAG} ${BPF_TIP_COMMIT}
 git branch ${SQUASH_BASE_TAG} ${SQUASH_COMMIT}
 git checkout -b ${SQUASH_TIP_TAG} ${SQUASH_COMMIT}
 
-# Validate there are no non-empty merges in bpf-next and bpf trees
-validate_merges ${BASELINE_TAG} ${TIP_TAG}
-validate_merges ${BPF_BASELINE_TAG} ${BPF_TIP_TAG}
-
 # Cherry-pick new commits onto squashed baseline commit
 cherry_pick_commits ${BASELINE_TAG} ${TIP_TAG}
 cherry_pick_commits ${BPF_BASELINE_TAG} ${BPF_TIP_TAG}