digsig: sort includes in digsig_cache.c

Sort header inclusions in digsig_cache.c, moving local inclusions below
kernel headers.

Signed-off-by: Rupert Muchembled <rupert@rmuch.net>
digsig: fix spacing in digsig_revocation.c

Fix whitespace errors in digsig_revocation.c, reported by
checkpatch.pl.

Signed-off-by: Rupert Muchembled <rupert@rmuch.net>
digsig: replace asm/uaccess.h in digsig_revocation.c

Replace asm/uaccess.h inclusion with linux/uaccess.h in
digsig_revocation.c.

Signed-off-by: Rupert Muchembled <rupert@rmuch.net>