bio-integrity: remove EXPORT_SYMBOL for bio_integrity_init_slab()

I got section mismatch message about bio_integrity_init_slab().

WARNING: fs/built-in.o(__ksymtab+0xb60): Section mismatch in reference from the variable __ksymtab_bio_integrity_init_slab to the function .init.text:bio_integrity_init_slab()

The symbol bio_integrity_init_slab is exported and annotated __init Fix
this by removing the __init annotation of bio_integrity_init_slab or drop
the export.

It only call from init_bio().  The EXPORT_SYMBOL() can be removed.
Signed-off-by: NYoichi Yuasa <yoichi_yuasa@tripeaks.co.jp>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: NAndrew Morton <akpm@linux-foundation.org>
Signed-off-by: NLinus Torvalds <torvalds@linux-foundation.org>

fs/bio-integrity.c

@@ -705,7 +705,6 @@ void __init bio_integrity_init_slab(void)
 	bio_integrity_slab = KMEM_CACHE(bio_integrity_payload,
 					SLAB_HWCACHE_ALIGN|SLAB_PANIC);
 }
-EXPORT_SYMBOL(bio_integrity_init_slab);
 
 static int __init integrity_init(void)
 {