seq_file: constify seq_operations

Make all seq_operations structs const, to help mitigate against
revectoring user-triggerable function pointers.

This is derived from the grsecurity patch, although generated from scratch
because it's simpler than extracting the changes from there.

Signed-off-by: James Morris <jmorris@namei.org>
Acked-by: Serge Hallyn <serue@us.ibm.com>
Acked-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

drivers/char/misc.c

@@ -91,7 +91,7 @@ static int misc_seq_show(struct seq_file *seq, void *v)
 }
 
 
-static struct seq_operations misc_seq_ops = {
+static const struct seq_operations misc_seq_ops = {
 	.start = misc_seq_start,
 	.next  = misc_seq_next,
 	.stop  = misc_seq_stop,

drivers/char/tpm/tpm_bios.c

@@ -343,14 +343,14 @@ static int tpm_ascii_bios_measurements_show(struct seq_file *m, void *v)
 	return 0;
 }
 
-static struct seq_operations tpm_ascii_b_measurments_seqops = {
+static const struct seq_operations tpm_ascii_b_measurments_seqops = {
 	.start = tpm_bios_measurements_start,
 	.next = tpm_bios_measurements_next,
 	.stop = tpm_bios_measurements_stop,
 	.show = tpm_ascii_bios_measurements_show,
 };
 
-static struct seq_operations tpm_binary_b_measurments_seqops = {
+static const struct seq_operations tpm_binary_b_measurments_seqops = {
 	.start = tpm_bios_measurements_start,
 	.next = tpm_bios_measurements_next,
 	.stop = tpm_bios_measurements_stop,