ANDROID: GKI: fix up build break where timer_delete_sync() was used

We reverted the commit that renamed del_timer_sync() to
timer_delete_sync() a long while back, but that broke the build when
commit 5071beb5 ("tcp/dccp: Don't use timer_pending() in
reqsk_queue_unlink().") was applied.  So fix it up to use the old
function name instead, allowing the build to work properly.

Fixes: 5071beb5 ("tcp/dccp: Don't use timer_pending() in reqsk_queue_unlink().")
Change-Id: I88112c8da97506f5c0028119f318ae8f730105fa
Signed-off-by: Greg Kroah-Hartman <gregkh@google.com>