sbin/hammer: Update blockmap lookup error#
The previous commit has removed -3, so update the existing ones.
We want to keep different numbers for each for debugging purpose
for hammer show command. hammer show prints these error codes.
Note that hammer show on the current production release (4.4)
doesn't directly print error code, but instead prints a string
(that doesn't contain the error code digit within char[]).
hammer show's output format has changed quite a bit in 4.5, and
directly showing error code is one of them. This commit doesn't
confuse 4.4 users, in other words it doesn't make hammer show
print "-3" on what was -4 in 4.4, since 4.4 doesn't print the
code itself.