perf: arm64: Record the user-mode PC in the call chain.

With this change, we no longer lose the innermost entry in the user-mode
part of the call chain.  See also the x86 port, which includes the ip,
and the corresponding change in arch/arm.
Signed-off-by: Jed Davis <jld@mozilla.com>
Acked-by: Ingo Molnar <mingo@kernel.org>
Acked-by: Will Deacon <will.deacon@arm.com>
Cc: stable@vger.kernel.org
Signed-off-by: Catalin Marinas <catalin.marinas@arm.com>

arch/arm64/kernel/perf_event.c

@@ -1336,6 +1336,7 @@ void perf_callchain_user(struct perf_callchain_entry *entry,
 		return;
 	}
 
+	perf_callchain_store(entry, regs->pc);
 	tail = (struct frame_tail __user *)regs->regs[29];
 
 	while (entry->nr < PERF_MAX_STACK_DEPTH &&