LU-12204 mke2fs: fix check for absurdly large devices

LU-12204 mke2fs: fix check for absurdly large devices

The check in mke2fs is intended to be for the number of blocks in the
filesystem exceeding the maximum number of addressable blocks in 2^32
bitmaps, which is (2^32 * 8 bits/byte * blocksize) = 2^47 blocks,
or 2^59 bytes = 512PiB for the common 4KiB blocksize.

However, s_log_blocksize holds log2(blocksize_in_kb), so the current
calculation is a factor of 2^10 too small.  This caused mke2fs to fail
while trying to format a 900TB filesystem.

Fixes: 101ef2e93c25 ("mke2fs: Avoid crashes / infinite loops for absurdly large devices")
Signed-off-by: Andreas Dilger <adilger@dilger.ca>
Change-Id: If6881e19c28d0c98848b9b4ede65b11d81dcab07
Reviewed-on: https://review.whamcloud.com/34762
Reviewed-by: Li Dongyang <dongyangli@ddn.com>
Tested-by: Andreas Dilger <adilger@whamcloud.com>