objtool/klp: Fix unexported static call key access for manually built livepatch modules

Enabling CONFIG_MEM_ALLOC_PROFILING_DEBUG with CONFIG_SAMPLE_LIVEPATCH
results in the following error:

samples/livepatch/livepatch-shadow-fix1.o: error: objtool: static_call: can't find static_call_key symbol: __SCK__WARN_trap

This is caused an extra file->klp sanity check which was added by commit
164c9201e1da ("objtool: Add base objtool support for livepatch
modules"). That check was intended to ensure that livepatch modules
built with klp-build always have full access to their static call keys.

However, it failed to account for the fact that manually built livepatch
modules (i.e., not built with klp-build) might need access to unexported
static call keys, for which read-only access is typically allowed for
modules.

While the livepatch-shadow-fix1 module doesn't explicitly use any static
calls, it does have a memory allocation, which can cause
CONFIG_MEM_ALLOC_PROFILING_DEBUG to insert a WARN() call. And WARN() is
now an unexported static call as of commit 860238af7a33 ("x86_64/bug:
Inline the UD1").

Fix it by removing the overzealous file->klp check, restoring the
original behavior for manually built livepatch modules.

Fixes: 164c9201e1da ("objtool: Add base objtool support for livepatch modules")
Reported-by: Arnd Bergmann <[e-mail]>
Acked-by: Song Liu <[e-mail]>
Tested-by: Arnd Bergmann <[e-mail]>
Link: https://patch.msgid.link/[e-mail]
Signed-off-by: Josh Poimboeuf <[e-mail]>

tools/objtool/check.c

···
 
 		key_sym = find_symbol_by_name(file->elf, tmp);
 		if (!key_sym) {
-			if (!opts.module || file->klp) {
+			if (!opts.module) {
 				ERROR("static_call: can't find static_call_key symbol: %s", tmp);
 				return -1;
 			}