objtool: Fix address references in alternatives

objtool: Fix address references in alternatives

When using the --disas option, alternatives are disassembled but
address references in non-default alternatives can be incorrect.

The problem is that alternatives are shown as if they were replacing the
original code of the alternative. So if an alternative is referencing
an address inside the alternative then the reference has to be
adjusted to the location of the original code.

Signed-off-by: Alexandre Chartre <alexandre.chartre@oracle.com>
Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org>
Acked-by: Josh Poimboeuf <jpoimboe@kernel.org>
Link: https://patch.msgid.link/20251121095340.464045-25-alexandre.chartre@oracle.com