ext4: hash: simplify kzalloc(n * 1, ...) to kzalloc(n, ...)

sizeof(char) evaluates to 1. Remove the churn.

Signed-off-by: Ethan Carter Edwards <ethan@ethancedwards.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://patch.msgid.link/20250316-ext4-hash-kcalloc-v2-1-2a99e93ec6e0@ethancedwards.com


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