module/*.ko: prune .data, global .rodata

Evaluated every variable that lives in .data (and globals in .rodata)
in the kernel modules, and constified/eliminated/localised them
appropriately. This means that all read-only data is now actually
read-only data, and, if possible, at file scope. A lot of previously-
global-symbols became inlinable (and inlined!) constants. Probably
not in a big Wowee Performance Moment, but hey.

Reviewed-by: Brian Behlendorf <behlendorf1@llnl.gov>
Signed-off-by: Ahelenia Ziemiańska <nabijaczleweli@nabijaczleweli.xyz>
Closes #12899

module/icp/api/kcf_miscapi.c

@@ -62,7 +62,7 @@ static kcf_ntfy_elem_t *ntfy_list_head;
  *	CRYPTO_MECH_INVALID otherwise.
  */
 crypto_mech_type_t
-crypto_mech2id(char *mechname)
+crypto_mech2id(const char *mechname)
 {
 	return (crypto_mech2id_common(mechname, B_TRUE));
 }