### Description

TLSF mem manager accounting for wrong values

was trying to debug a crash and this popped up.

using a lot of small allocs until pkg_alloc returns NULL (when exhausted) when NULL is returned the memory **used+overhead** exceeds the heap allocated. <!-- -->

### Troubleshooting

#### Reproduction

use frequent small memory allocs until pool is exausted (returns NULL) , check tlsf status.

static void do_test_mem() { void* chunk; tlsf_t pool = NULL; size_t total = 16 * 1024 * 1024; size_t half = 8 * 1024 * 1024; size_t sz = 6; int x; void* mem = malloc(total); char* mem2 = tlsf_cast(char*, tlsf_cast(ptrdiff_t, mem) + half); memset(mem2, 'X', half); assert(*mem2 == 'X'); pool = tlsf_create_with_pool(mem, half); do { chunk = tlsf_malloc(pool, sz); } while(chunk != NULL); tlsf_status(pool); for(x=0; x < half; x++) { assert(*mem2 == 'X'); mem2++; } free(mem); }

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``` heap size= **8388592** used= **6285144**, used+overhead=**12578696**, free=**18446744073705361512**, fragments=0 max used (+overhead)=12578696, max fragments=1 Free blocks matrix ('.': none, 'X': between 2^X and (2^(X+1)-1) free blocks, X=A..Z, A=0, B=1, ...)

first-level: 32 block list arrays between 2^fl and 2^(fl+1) bytes (fl=8..39)

v second-level: 32 block lists between 2^fl+sl*2^(fl-5) and 2^fl+(sl+1)*2^(fl-5)-1 bytes (sl=0..31) 0|................................| 1|................................| 2|................................| 3|................................| 4|................................| 5|................................| 6|................................| 7|................................| 8|................................| 9|................................| 10|................................| 11|................................| 12|................................| 13|................................| 14|................................| 15|................................| 16|................................| 17|................................| 18|................................| 19|................................| 20|................................| 21|................................| 22|................................| 23|................................| 24|................................| 25|................................| 26|................................| 27|................................| 28|................................| 29|................................| 30|................................| 31|................................| ```

#### Log Messages

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``` identical to reproduce step when calling mem debug on a running instance ```

### Possible Solutions

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### Additional Information

``` * **Kamailio Version** - built from master ```

* **Operating System**:

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``` CentOS7 and alpine ```

## comments

heap size= **8388592** shouldn't it be **8388608** ? used+overhead=**12578696** misleading free=**18446744073705361512** misleading, looks like it has a negative value the map doesn't look ok (or i'm not understanding what it should show), its the same output before the alloc and after.