Update kernel to builds 7915175

git log --first-parent -100 --oneline --no-decorate 7eb444cc279e..b9c4f1b9b54a:
b9c4f1b9b54a ANDROID: ABI: Update symbols to unisoc whitelist for the twentieth time
60bad4df861d ANDROID: userfaultfd: Fix untag pointer in userfaultfd_continue()
f49f3b377eae ANDROID: GKI: rework the ANDROID_KABI_USE() macro to not use __UNIQUE()
2138e7367558 ANDROID: Incremental fs: Fix dentry get/put imbalance on vfs_mkdir() failure
cbb80ec0faf2 ANDROID: f2fs: fix potential deadlock by android ftrace

Test: treehugger
Bug: 206745249
Change-Id: Idf2699a8b6ecd7f875c733fd8cbefe616d100de5