Fixes the following build errors under GCC 11:

  In file included from ../block/blk-crypto.c:14:
  ../block/blk-crypto.c: In function 'blk_crypto_flock':
  ../include/linux/keyslot-manager.h:101:13: error: inlining failed in call to 'always_inline' 'ksm_flock': function body not available
    101 | inline void ksm_flock(struct keyslot_manager *ksm, unsigned int flags);
        |             ^~~~~~~~~
  ../block/blk-crypto.c:310:9: note: called from here
    310 |         ksm_flock(ksm, flags);
        |         ^~~~~~~~~~~~~~~~~~~~~

  In file included from ../drivers/md/dm.c:27:
  ../drivers/md/dm.c: In function 'dm_derive_raw_secret_callback':
  ../include/linux/blk-crypto.h:35:13: error: inlining failed in call to 'always_inline' 'blk_crypto_flock': function body not available
     35 | inline void blk_crypto_flock(struct keyslot_manager *ksm, unsigned int flags);
        |             ^~~~~~~~~~~~~~~~
  ../drivers/md/dm.c:2120:17: note: called from here
   2120 |                 blk_crypto_flock(dev->bdev->bd_queue->ksm, SINGLE_DEPTH_NESTING);
        |                 ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
---
diff --git a/block/blk-crypto.c b/block/blk-crypto.c
index f15ed0b70ecd..703700d9bf9d 100644
--- a/block/blk-crypto.c
+++ b/block/blk-crypto.c
@@ -305,7 +305,7 @@ int blk_crypto_evict_key(struct request_queue *q,
 }
 EXPORT_SYMBOL_GPL(blk_crypto_evict_key);
 
-inline void blk_crypto_flock(struct keyslot_manager *ksm, unsigned int flags)
+void blk_crypto_flock(struct keyslot_manager *ksm, unsigned int flags)
 {
 	ksm_flock(ksm, flags);
 }
diff --git a/block/keyslot-manager.c b/block/keyslot-manager.c
index 1ce66f66af20..95afcd9c4874 100644
--- a/block/keyslot-manager.c
+++ b/block/keyslot-manager.c
@@ -681,7 +681,7 @@ EXPORT_SYMBOL_GPL(keyslot_manager_derive_raw_secret);
  * detection, set another lock sub-class could avoid it.
  *
  */
-inline void ksm_flock(struct keyslot_manager *ksm, unsigned int flags)
+void ksm_flock(struct keyslot_manager *ksm, unsigned int flags)
 {
 	ksm->lock_flags = flags;
 }
diff --git a/include/linux/blk-crypto.h b/include/linux/blk-crypto.h
index 43d0dbbeb70f..30ba27226a22 100644
--- a/include/linux/blk-crypto.h
+++ b/include/linux/blk-crypto.h
@@ -32,7 +32,7 @@ int blk_crypto_start_using_mode(enum blk_crypto_mode_num crypto_mode,
 int blk_crypto_evict_key(struct request_queue *q,
 			 const struct blk_crypto_key *key);
 
-inline void blk_crypto_flock(struct keyslot_manager *ksm, unsigned int flags);
+void blk_crypto_flock(struct keyslot_manager *ksm, unsigned int flags);
 
 
 #else /* CONFIG_BLK_INLINE_ENCRYPTION */
diff --git a/include/linux/keyslot-manager.h b/include/linux/keyslot-manager.h
index e247be8a5d43..dfb1d97d8fb6 100644
--- a/include/linux/keyslot-manager.h
+++ b/include/linux/keyslot-manager.h
@@ -98,7 +98,7 @@ int keyslot_manager_derive_raw_secret(struct keyslot_manager *ksm,
 				      unsigned int wrapped_key_size,
 				      u8 *secret, unsigned int secret_size);
 
-inline void ksm_flock(struct keyslot_manager *ksm, unsigned int flags);
+void ksm_flock(struct keyslot_manager *ksm, unsigned int flags);
 
 #endif /* CONFIG_BLK_INLINE_ENCRYPTION */