bcache: remove unnecessary select MIN_HEAP

After reverting the transition to the generic min heap library, bcache no
longer depends on MIN_HEAP.  The select entry can be removed to reduce
code size and shrink the kernel's attack surface.

This change effectively reverts the bcache-related part of commit
92a8b224b8 ("lib/min_heap: introduce non-inline versions of min heap API
functions").

This is part of a series of changes to address a performance regression
caused by the use of the generic min_heap implementation.

As reported by Robert, bcache now suffers from latency spikes, with P100
(max) latency increasing from 600 ms to 2.4 seconds every 5 minutes. 
These regressions degrade bcache's effectiveness as a low-latency cache
layer and lead to frequent timeouts and application stalls in production
environments.

Link: https://lore.kernel.org/lkml/CAJhEC05+0S69z+3+FB2Cd0hD+pCRyWTKLEOsc8BOmH73p1m+KQ@mail.gmail.com
Link: https://lkml.kernel.org/r/[email protected]
Fixes: 866898efbb ("bcache: remove heap-related macros and switch to generic min_heap")
Fixes: 92a8b224b8 ("lib/min_heap: introduce non-inline versions of min heap API functions")
Signed-off-by: Kuan-Wei Chiu <[email protected]>
Reported-by: Robert Pang <[email protected]>
Closes: https://lore.kernel.org/linux-bcache/CAJhEC06F_AtrPgw2-7CvCqZgeStgCtitbD-ryuPpXQA-JG5XXw@mail.gmail.com
Acked-by: Coly Li <[email protected]>
Cc: Ching-Chun (Jim) Huang <[email protected]>
Cc: Kent Overstreet <[email protected]>
Cc: <[email protected]>
Signed-off-by: Andrew Morton <[email protected]>

drivers/md/bcache/Kconfig

@@ -5,7 +5,6 @@ config BCACHE
 	select BLOCK_HOLDER_DEPRECATED if SYSFS
 	select CRC64
 	select CLOSURES
-	select MIN_HEAP
 	help
 	Allows a block device to be used as cache for other devices; uses
 	a btree for indexing and the layout is optimized for SSDs.