[PATCH 1/3] pstore: Adjust buffer size for compression for smaller registered buffers

[Luck, Tony]

-	big_oops_buf_sz = (psinfo->bufsize * 100) / 45;
+	big_oops_buf_sz = (psinfo->bufsize * 100) / cmpr;

Tested on an ERST backed system.  Seems to be working (we save a little less information
per ERST record than before this change (uncompressed size goes down from ~17500 to
~16400 bytes) - but this patch switched the denominator from 45 to 48 (for ERST) - so that
seems plausible.

Seiji: let me know how the efivars tests go.

-Tony