IMA: remove -Wmissing-prototypes warning

stable inclusion
from stable-5.10.65
commit 5cc1ee31353bd45e236c8679ebb561a5ee65fc5c
bugzilla: 182361 https://gitee.com/openeuler/kernel/issues/I4EH3U

Reference: https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/commit/?id=5cc1ee31353bd45e236c8679ebb561a5ee65fc5c

--------------------------------

commit a32ad904 upstream.

With W=1 build, the compiler throws warning message as below:

   security/integrity/ima/ima_mok.c:24:12: warning:
   no previous prototype for ‘ima_mok_init’ [-Wmissing-prototypes]
       __init int ima_mok_init(void)

Silence the warning by adding static keyword to ima_mok_init().
Signed-off-by: NAustin Kim <austin.kim@lge.com>
Fixes: 41c89b64 ("IMA: create machine owner and blacklist keyrings")
Cc: stable@vger.kernel.org
Signed-off-by: NMimi Zohar <zohar@linux.ibm.com>
Signed-off-by: NGreg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Acked-by: NWeilong Chen <chenweilong@huawei.com>
Signed-off-by: NChen Jun <chenjun102@huawei.com>
Signed-off-by: NZheng Zengkai <zhengzengkai@huawei.com>

security/integrity/ima/ima_mok.c

@@ -21,7 +21,7 @@ struct key *ima_blacklist_keyring;
 /*
  * Allocate the IMA blacklist keyring
  */
-__init int ima_mok_init(void)
+static __init int ima_mok_init(void)
 {
 	struct key_restriction *restriction;