The KUnit test suite turned insert_extent() and sort_idmaps() into global
symbols and declared them in include/linux/user_namespace.h. That header
is pulled in nearly everywhere through linux/cgroup.h and the btrfs
self-tests carry a static insert_extent() of their own, so any config
with both test suites enabled fails to build:

  fs/btrfs/tests/inode-tests.c:16:13: error: conflicting types for 'insert_extent'
  include/linux/user_namespace.h:212:12: note: previous declaration of 'insert_extent'

A global symbol needs a prefix. Rename them to
uid_gid_map_insert_extent() and uid_gid_map_sort(). It's the better name
anyway.

No functional changes.

Fixes: f6f1a2496ba5 ("userns: Add KUnit test suite for uid_gid_map")
Reported-by: kernel test robot <lkp@intel.com>
Closes: https://lore.kernel.org/oe-kbuild-all/202609110843.okbPe7GM-lkp@intel.com/
Closes: https://lore.kernel.org/oe-kbuild-all/202609110937.zHKPPXJk-lkp@intel.com/
Link: https://patch.msgid.link/20260911-suggerieren-suchaktion-fliehen-87b9cdf1d169@brauner
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

Add a KUnit test suite to verify the insertion and sorting of mappings
in struct uid_gid_map. This test suite validates both base extent
insertion (<= 5 mappings) and extended extent insertion (> 5 mappings,
which triggers the allocation of the forward and reverse pointers).

This is especially useful for verifying that the __counted_by_ptr
attribute added to 'forward' and 'reverse' pointers works correctly
without causing any runtime bounds-checking panics or traps.

Signed-off-by: Bill Wendling <morbo@google.com>
Link: https://patch.msgid.link/20260908222734.3048684-2-morbo@google.com
Tested-by: Bradley Morgan <brads@mainlining.org>
Reviewed-by: Bradley Morgan <brads@mainlining.org>
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>