cr50: unwrap BUILD_ASSERTs in virtual_nvmem.c
cr50: unwrap BUILD_ASSERTs in virtual_nvmem.c

This is a cosmetic CL that gets rid of breaking BUILD_ASSERT statements
in virtual_nvmem.c into two lines since they all fit 80 chars.

BRACH=none
BUG=none
TEST=build

Change-Id: Iaec1115101c36d8ec20967c64931666b760b027d
Signed-off-by: Andrey Pronin <53bbebe6910b11f7aa2d1daaa466658eb4cba5f2@chromium.org>
Reviewed-on: https://chromium-review.googlesource.com/c/chromiumos/platform/ec/+/1679595
Reviewed-by: Vadim Bendebury <5515d6d2d0829cbe0dd0dcf2094aaded06d58514@chromium.org>
Reviewed-by: Louis Collard <591722de08e49b258a33cc28248aa0c58c1a6929@chromium.org>

coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec,coreboot/chrome-ec