hrtimer: Fix incorrect #endif comment for BITS_PER_LONG check

hrtimer: Fix incorrect #endif comment for BITS_PER_LONG check

The #endif comment says "BITS_PER_LONG >= 64", but the corresponding #if
guard is "BITS_PER_LONG < 64".

The comment was originally correct when the block had a three-way
#if/#else/#endif structure, where the #else branch provided a 64-bit inline
version.  Commit 79bf2bb335b8 ("[PATCH] tick-management: dyntick / highres
functionality") removed the #else branch but did not update the #endif
comment, leaving it inconsistent with the remaining #if condition.

Fix the comment to match the preprocessor guard.

Signed-off-by: Zhan Xusheng <zhanxusheng@xiaomi.com>
Signed-off-by: Thomas Gleixner <tglx@kernel.org>
Link: https://patch.msgid.link/20260331074811.26147-1-zhanxusheng@xiaomi.com