integrity: Remove references to module keyring

From what I can tell, it has never been used.

Mimi: This was introduced prior to Rusty's decision to use appended
signatures for kernel modules.
Signed-off-by: Thiago Jung Bauermann <bauerman@linux.ibm.com>
Acked-by: Mimi Zohar <zohar@linux.ibm.com>
Signed-off-by: James Morris <james.morris@microsoft.com>

security/integrity/digsig.c

@@ -34,7 +34,6 @@ static const char * const keyring_name[INTEGRITY_KEYRING_MAX] = {
 	".evm",
 	".ima",
 #endif
-	"_module",
 	".platform",
 };
 

security/integrity/integrity.h

@@ -141,9 +141,8 @@ int integrity_kernel_read(struct file *file, loff_t offset,
 
 #define INTEGRITY_KEYRING_EVM		0
 #define INTEGRITY_KEYRING_IMA		1
-#define INTEGRITY_KEYRING_MODULE	2
-#define INTEGRITY_KEYRING_PLATFORM	3
-#define INTEGRITY_KEYRING_MAX		4
+#define INTEGRITY_KEYRING_PLATFORM	2
+#define INTEGRITY_KEYRING_MAX		3
 
 extern struct dentry *integrity_dir;