TT#86451 hooks/pre-commit: ensure to always execute in main ngcpcfg directory

When `ngcpcfg commit ...` is executed from inside a git repository as
its working directory (like `/etc/`), then the initial `git rev-parse
--git-dir` invocation does *not* fail.

This results in not switching into the appropriate main directory
(`/etc/ngcp-config/`), but instead continue to run in the working
directory and create the .ngcpcfg_perms at the wrong place (like `/etc/`
instead of `/etc/ngcp-config/`).

Change-Id: Ic9da1f306274d3ba1d9d97dfe77e39094aa2127a

hooks/pre-commit

@@ -4,14 +4,13 @@
 
 set -e
 
-# ensure we're in the appropriate git directory when invoked directly
-# e.g. via `/etc/ngcp-config/.git/hooks/pre-commit` inside ngcpcfg
-if ! git rev-parse --git-dir >/dev/null 2>&1 ; then
-  cd "$(dirname "${0}")"
-  if git rev-parse --git-dir >/dev/null 2>&1 ; then
-    git_dir="$(git rev-parse --git-dir)"
-    cd "$(dirname "${git_dir}")"
-  fi
+# ensure we're in the appropriate git directory (/etc/ngcp-config/ by default),
+# we don't rely on ${NGCPCTL_MAIN} just in case we're invoked directly,
+# e.g. via `/etc/ngcp-config/.git/hooks/pre-commit` (outside of ngcpcfg)
+cd "$(dirname "${0}")"
+if git rev-parse --git-dir >/dev/null 2>&1 ; then
+  git_dir="$(git rev-parse --git-dir)"
+  cd "$(dirname "${git_dir}")"
 fi
 
 if ! git rev-parse --git-dir >/dev/null 2>&1 ; then