Check search state when cancel read remote name procedure

Application may call cancel_discovery when the stack is doing
create_bond. The bonding process fails, because cancel_discovery
causes to cancel remote name request procedure.

Bug:154074383
Test: CtsVerifier->Bluetooth Test->Bluetooth HID Host
Change-Id: Icadf9abe342fffdf06b9623fb5c7e6de05a337bc
(cherry picked from commit e3f9fe7425705dc819a638c158ad9f87cb2bd1eb)