commit-slabs: remove realloc counter outside of slab struct

The realloc counter is declared outside the struct for the given slabname,
which makes it harder for a follow up patch to move the declaration of the
struct around as then the counter variable would need special treatment.

As the reallocation counter is currently unused we can just remove it.
If we ever need to count the reallocations again, we can reintroduce
the counter as part of 'struct slabname' in commit-slab-decl.h.

Signed-off-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

commit-slab-impl.h

@@ -11,8 +11,6 @@
 
 #define implement_commit_slab(slabname, elemtype, scope)		\
 									\
-static int stat_ ##slabname## realloc;					\
-									\
 scope void init_ ##slabname## _with_stride(struct slabname *s,		\
 						   unsigned stride)	\
 {									\
@@ -54,7 +52,6 @@ scope elemtype *slabname## _at_peek(struct slabname *s,			\
 		if (!add_if_missing)					\
 			return NULL;					\
 		REALLOC_ARRAY(s->slab, nth_slab + 1);			\
-		stat_ ##slabname## realloc++;				\
 		for (i = s->slab_count; i <= nth_slab; i++)		\
 			s->slab[i] = NULL;				\
 		s->slab_count = nth_slab + 1;				\