random: entropy_bytes is actually bits

The variable 'entropy_bytes' is set from an expression that actually
counts bits.  Fortunately it's also only compared to values that also
count bits.  Rename it accordingly.

Signed-off-by: Greg Price <price@mit.edu>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

diff --cc drivers/char/random.c
Simple merge