objtool: Fix function fallthrough detection for vmlinux

Bugzilla: https://bugzilla.redhat.com/show_bug.cgi?id=2121207



commit 08feafe8
Author: Josh Poimboeuf <jpoimboe@redhat.com>
Date:   Mon Apr 11 16:10:32 2022 -0700

    objtool: Fix function fallthrough detection for vmlinux

    Objtool's function fallthrough detection only works on C objects.
    The distinction between C and assembly objects no longer makes sense
    with objtool running on vmlinux.o.

    Now that copy_user_64.S has been fixed up, and an objtool sibling call
    detection bug has been fixed, the asm code is in "compliance" and this
    hack is no longer needed.  Remove it.

    Fixes: ed53a0d9 ("x86/alternative: Use .ibt_endbr_seal to seal indirect calls")
Signed-off-by: Josh Poimboeuf <jpoimboe@redhat.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
    Link: https://lkml.kernel.org/r/b434cff98eca3a60dcc64c620d7d5d405a0f441c.1649718562.git.jpoimboe@redhat.com



Signed-off-by: Joe Lawrence <joe.lawrence@redhat.com>