IMA: Update KBUILD_MODNAME for IMA files to ima

The kbuild Makefile specifies object files for vmlinux in the $(obj-y)
lists. These lists depend on the kernel configuration[1].

The kbuild Makefile for IMA combines the object files for IMA into a
single object file namely ima.o. All the object files for IMA should be
combined into ima.o. But certain object files are being added to their
own $(obj-y). This results in the log messages from those modules getting
prefixed with their respective base file name, instead of "ima". This is
inconsistent with the log messages from the IMA modules that are combined
into ima.o.

This change fixes the above issue.

[1] Documentation\kbuild\makefiles.rst
Signed-off-by: Tushar Sugandhi <tusharsu@linux.microsoft.com>
Reviewed-by: Mimi Zohar <zohar@linux.ibm.com>
Reviewed-by: Lakshmi Ramasubramanian <nramas@linux.microsoft.com>
Signed-off-by: Mimi Zohar <zohar@linux.ibm.com>

security/integrity/ima/Makefile

@@ -11,6 +11,6 @@ ima-y := ima_fs.o ima_queue.o ima_init.o ima_main.o ima_crypto.o ima_api.o \
 ima-$(CONFIG_IMA_APPRAISE) += ima_appraise.o
 ima-$(CONFIG_IMA_APPRAISE_MODSIG) += ima_modsig.o
 ima-$(CONFIG_HAVE_IMA_KEXEC) += ima_kexec.o
-obj-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
-obj-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o
-obj-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o
+ima-$(CONFIG_IMA_BLACKLIST_KEYRING) += ima_mok.o
+ima-$(CONFIG_IMA_MEASURE_ASYMMETRIC_KEYS) += ima_asymmetric_keys.o
+ima-$(CONFIG_IMA_QUEUE_EARLY_BOOT_KEYS) += ima_queue_keys.o