interfacesEqual: not templatized, use const sp&.

So, this will save space when the function is used, and it'll also
save copies (when the object is already of this type, otherwise, the
conversion constructor will still be invoked).

Bug: 118394906
Test: boot, hidl_test

Change-Id: I3cb81d578df43e9e91d54f52945c0c44cc35208e
2 files changed