crypto: shash - remove excess kerneldoc members

Commit 42808e5d ("crypto: hash - Count error stats differently")
moved some fields from 'struct shash_alg' into HASH_ALG_COMMON but
didn't remove the corresponding kerneldoc members, which results in
these warnings when running 'make htmldocs':

  ./include/crypto/hash.h:248: warning: Excess struct member 'digestsize' description in 'shash_alg'
  ./include/crypto/hash.h:248: warning: Excess struct member 'statesize' description in 'shash_alg'
  ./include/crypto/hash.h:248: warning: Excess struct member 'stat' description in 'shash_alg'
  ./include/crypto/hash.h:248: warning: Excess struct member 'base' description in 'shash_alg'

HASH_ALG_COMMON already has the documentation for all these fields.

Fixes: 42808e5d ("crypto: hash - Count error stats differently")
Cc: Randy Dunlap <rdunlap@infradead.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Vegard Nossum <vegard.nossum@oracle.com>
Reviewed-by: Randy Dunlap <rdunlap@infradead.org>
Tested-by: Randy Dunlap <rdunlap@infradead.org>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>