BLE Host - Don't crash if no store package.
BLE Host - Don't crash if no store package.

Prior to this change: the host asserted that IRK restoration succeeds at
sync time.  A common reason for failure was the lack of any host store
package in the build.

After change: If IRK restoration at startup fails for any reason, a
message is logged and the app continues running.

X-Original-Commit: 3e6ff4de76f6cc486ad7c7a545c3f8b4aac01e82

apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble,apache/mynewt-nimble