logd: identical check access message data out of range

(cherry pick from commit 22712428)

Discovered while running AddressSanitizer, binary events were fed
into logd that were smaller than the binary event string header.
Fix is to check the buffer sizes before performing the memcmp
operation.

Test: compile
Bug: 74574189
Change-Id: Ic01ef6fb0725258d9f39bbdca582ed648a1adc5d